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Kusintha kwa tizilombo toyambitsa matenda kumaphatikizapo kulimbana pakati pa kusankha kwachilengedwe, komwe kumapangitsa kuti tizilombo toyambitsa matenda tiwongolere, ndi kusintha kwa majini, komwe kumapangitsa kuti tizilombo toyambitsa matenda titaye majini ndikusonkhanitsa masinthidwe owononga. Pano, kuti timvetse momwe kulimbana kumeneku kumachitikira pamlingo wa macromolecule imodzi, tikufotokoza kapangidwe ka cryo-EM ka ribosome ya Encephalitozoon cuniculi, chamoyo cha eukaryotic chomwe chili ndi genome yaying'ono kwambiri m'chilengedwe. Kuchepa kwakukulu kwa rRNA mu E. cuniculi ribosomes kumayenderana ndi kusintha kwa kapangidwe komwe sikunachitikepo, monga kusintha kwa ma rRNA linkers osadziwika kale ndi rRNA opanda ma bulges. Kuphatikiza apo, E. cuniculi ribosome idapulumuka kutayika kwa zidutswa za rRNA ndi mapuloteni mwa kupanga luso logwiritsa ntchito mamolekyu ang'onoang'ono ngati ma structural examples a rRNA fragments ndi mapuloteni omwe awonongeka. Ponseponse, tikuwonetsa kuti ma molekyulu omwe amaganiziridwa kuti achepetsedwa, amawonongeka, komanso amatha kusintha molakwika ali ndi njira zingapo zolipirira zomwe zimawasunga akugwira ntchito ngakhale kuti mamolekyuluwo amachepa kwambiri.
Popeza magulu ambiri a tizilombo toyambitsa matenda ali ndi zida zapadera zogwiritsira ntchito mamolekyu awo, nthawi zambiri timayenera kupanga njira zosiyanasiyana zochiritsira magulu osiyanasiyana a tizilombo toyambitsa matenda1,2. Komabe, umboni watsopano ukusonyeza kuti mbali zina za kusintha kwa tizilombo toyambitsa matenda zimasinthasintha ndipo zimadziwikiratu, zomwe zikusonyeza maziko omwe angatheke ochiritsira ambiri mwa tizilombo toyambitsa matenda3,4,5,6,7,8,9.
Ntchito yapitayi yapeza njira yodziwika bwino yosinthira majeremusi a tizilombo toyambitsa matenda yotchedwa kuchepetsa majeremusi kapena kuwonongeka kwa majeremusi10,11,12,13. Kafukufuku wapano akuwonetsa kuti pamene tizilombo toyambitsa matenda tisiya moyo wawo wodziyimira tokha ndikukhala tizilombo toyambitsa matenda mkati mwa maselo (kapena ma endosymbionts), majini awo amasinthasintha pang'onopang'ono koma modabwitsa kwa zaka mamiliyoni ambiri9,11. Mu njira yotchedwa kuwonongeka kwa majini, tizilombo toyambitsa matenda timasonkhanitsa kusintha komwe kumasintha majini ambiri omwe kale anali ofunikira kukhala majini a pseudogenes, zomwe zimapangitsa kuti majini awonongeke pang'onopang'ono komanso kuwonongeka kwa majini14,15. Kugwa kumeneku kumatha kuwononga mpaka 95% ya majini m'zamoyo zakale kwambiri zamkati mwa maselo poyerekeza ndi mitundu yofanana ya moyo waulere. Chifukwa chake, kusintha kwa tizilombo toyambitsa matenda mkati mwa maselo ndi nkhondo yolimbana pakati pa mphamvu ziwiri zotsutsana: kusankha kwachilengedwe kwa Darwin, komwe kumabweretsa kusintha kwa tizilombo toyambitsa matenda, ndi kugwa kwa majini, zomwe zimapangitsa kuti tizilombo toyambitsa matenda tisadziwike. Momwe tizilombo toyambitsa matenda tidatulukira mu nkhondoyi ndikusunga ntchito ya kapangidwe kake ka molekyulu sikukudziwika bwino.
Ngakhale kuti njira yowola majini siikudziwika bwino, zikuoneka kuti imachitika makamaka chifukwa cha kusintha kwa majini pafupipafupi. Chifukwa tizilombo toyambitsa matenda timakhala m'magulu ang'onoang'ono, osagonana, komanso omwe ali ndi majini ochepa, sitingathe kuchotsa bwino kusintha kwa majini komwe nthawi zina kumachitika panthawi yobwerezabwereza kwa DNA. Izi zimapangitsa kuti pakhale kusonkhanitsa kosasinthika kwa kusintha kwa majini koopsa komanso kuchepetsa majini a tizilombo toyambitsa matenda. Zotsatira zake, tizilombo toyambitsa matenda sitingotaya majini omwe sali ofunikira kuti tipulumuke m'malo ozungulira maselo. Ndi kulephera kwa tizilombo toyambitsa matenda kuthetsa kusintha kwa majini komwe kumachitika nthawi ndi nthawi komwe kumapangitsa kuti kusinthaku kuchuluke mu majini onse, kuphatikizapo majini awo ofunikira kwambiri.
Zambiri zomwe tikumvetsa pakali pano zokhudza kuchepetsa majini zimachokera kokha kufananiza kwa ma genome, osayang'ana kwambiri kusintha kwa mamolekyu enieni omwe amagwira ntchito zosamalira nyumba ndipo amakhala ngati mankhwala omwe angakhalepo. Kafukufuku woyerekeza wasonyeza kuti vuto la kusintha kwa tizilombo toyambitsa matenda m'maselo likuwoneka kuti limapangitsa mapuloteni ndi ma nucleic acids kusokonekera ndikusonkhana, zomwe zimapangitsa kuti azidalira kwambiri chaperone komanso azimva kutentha19,20,21,22,23. Kuphatikiza apo, tizilombo toyambitsa matenda osiyanasiyana—kusintha kodziyimira pawokha nthawi zina komwe kumalekanitsidwa ndi zaka 2.5 biliyoni—adakumana ndi kutayika kofanana kwa malo owongolera khalidwe mu kapangidwe ka mapuloteni5,6 ndi njira zokonzanso DNA24. Komabe, zochepa zomwe zimadziwika za momwe moyo wamkati mwa maselo umakhudzira zinthu zina zonse za ma macromolecule a maselo, kuphatikizapo kusintha kwa mamolekyulu ku katundu wowonjezereka wa kusintha kwa masinthidwe olakwika.
Mu ntchito iyi, kuti timvetse bwino kusintha kwa mapuloteni ndi ma nucleic acid a tizilombo toyambitsa matenda m'maselo, tinapeza kapangidwe ka ma ribosome a tizilombo toyambitsa matenda m'maselo Encephalitozoon cuniculi. E. cuniculi ndi chamoyo chofanana ndi bowa chomwe chili m'gulu la microsporidia ya parasitic yomwe ili ndi majini ang'onoang'ono a eukaryotic ndipo motero imagwiritsidwa ntchito ngati zamoyo zoyeserera kuphunzira kuwonongeka kwa majini25,26,27,28,29,30. Posachedwapa, kapangidwe ka cryo-EM ribosome kanapezeka kuti kamapezeka majini ochepetsedwa pang'ono a Microsporidia, Paranosema locustae, ndi Vairimorpha necatrix31,32 (~3.2 Mb genome). Kapangidwe kameneka kakusonyeza kuti kutayika kwina kwa rRNA amplification kumalipidwa ndi chitukuko cha kulumikizana kwatsopano pakati pa mapuloteni a ribosomal oyandikana nawo kapena kupeza mapuloteni atsopano a msL131,32 ribosomal. Mitundu ya Encephalitozoon (genome ~2.5 miliyoni bp), pamodzi ndi wachibale wawo wapafupi kwambiri wa Ordospora, ikuwonetsa kuchuluka kwa kuchepa kwa majini a eukaryotes - ali ndi majini osakwana 2000 olembera mapuloteni, ndipo akuyembekezeka kuti ma ribosome awo samangokhala opanda zidutswa za rRNA expansion (zidutswa za rRNA zomwe zimasiyanitsa ma ribosome a eukaryotic ndi ma ribosome a bakiteriya) komanso ali ndi mapuloteni anayi a ribosomal chifukwa chosowa ma homologues mu genome ya E. cuniculi26,27,28. Chifukwa chake, tinatsimikiza kuti E. cuniculi ribosome ikhoza kuwulula njira zomwe sizinali zodziwika kale zosinthira mamolekyulu kuti awonongeke.
Kapangidwe kathu ka cryo-EM kakuyimira ribosome yaying'ono kwambiri ya eukaryotic cytoplasmic yomwe imadziwika ndipo imapereka chidziwitso cha momwe kuchuluka komaliza kwa kuchepa kwa majini kumakhudzira kapangidwe, kusonkhana, ndi kusintha kwa makina a molekyulu omwe ndi ofunikira ku selo. Tapeza kuti ribosome ya E. cuniculi imaphwanya mfundo zambiri zomwe zasungidwa kwambiri za kupangika kwa RNA ndi kusonkhana kwa ribosome, ndipo tapeza puloteni yatsopano, yomwe kale inali yosadziwika ya ribosomal. Mosayembekezereka, tikuwonetsa kuti ma microsporidia ribosomes apanga kuthekera komanga mamolekyu ang'onoang'ono, ndikuganiza kuti kudulidwa kwa rRNA ndi mapuloteni kumayambitsa zatsopano zomwe pamapeto pake zingapereke makhalidwe abwino pa ribosome.
Kuti timvetse bwino za kusintha kwa mapuloteni ndi ma nucleic acid m'zamoyo zamkati mwa maselo, tinaganiza zopatula ma E. cuniculi spores kuchokera ku mitundu ya maselo a nyama zomwe zili ndi kachilomboka kuti tiyeretse ma ribosome awo ndikupeza kapangidwe ka ma ribosome awa. N'zovuta kupeza ma microsporidia ambiri a parasitic chifukwa ma microsporidia sangakulitsidwe mu malo odyetsera zakudya. M'malo mwake, amakula ndikuberekana mkati mwa selo lokhalamo. Chifukwa chake, kuti tipeze E. cuniculi biomass kuti tiyeretse ribosome, tinayika kachilombo ka RK13 mu selo la impso la nyama zomwe zili ndi kachilomboka ndipo tinakulitsa maselo omwe ali ndi kachilomboka kwa milungu ingapo kuti E. cuniculi ikule ndikuchulukana. Pogwiritsa ntchito monolayer ya selo yomwe ili ndi kachilomboka ya pafupifupi theka la mita lalikulu, tinatha kuyeretsa pafupifupi 300 mg ya ma Microsporidia spores ndikuwagwiritsa ntchito kupatula ma ribosome. Kenako tinasokoneza ma spores oyeretsedwa ndi mikanda yagalasi ndikupatula ma ribosome osaphika pogwiritsa ntchito stepwise polyethylene glycol fractionation ya lysates. Izi zinatithandiza kupeza pafupifupi 300 µg ya ma ribosome a E. cuniculi osaphika kuti tiwunike kapangidwe kake.
Kenako tinasonkhanitsa zithunzi za cryo-EM pogwiritsa ntchito zitsanzo za ribosome zomwe zinatuluka ndipo tinazikonza pogwiritsa ntchito zigoba zofanana ndi gulu lalikulu la ribosomal, mutu wa gulu laling'ono, ndi gulu laling'ono. Pa nthawiyi, tinasonkhanitsa zithunzi za tinthu ta ribosomal pafupifupi 108,000 ndi zithunzi za cryo-EM zowerengedwa ndi resolution ya 2.7 Å (Zithunzi Zowonjezera 1-3). Kenako tinagwiritsa ntchito zithunzi za cryoEM kuti tiyerekeze rRNA, ribosomal protein, ndi hibernation factor Mdf1 yogwirizana ndi E. cuniculi ribosomes (Chithunzi 1a, b).
Kapangidwe ka E. cuniculi ribosome mu complex ndi hibernation factor Mdf1 (pdb id 7QEP). b Mapu a hibernation factor Mdf1 yogwirizana ndi E. cuniculi ribosome. c Mapu a kapangidwe kachiwiri akuyerekeza rRNA yobwezeretsedwa mu mitundu ya Microsporidian ndi kapangidwe kodziwika ka ribosomal. Mapanelo akuwonetsa malo omwe pali zidutswa za rRNA zolimbikitsidwa (ES) ndi malo omwe amagwira ntchito a ribosome, kuphatikiza malo ofotokozera (DC), sarcinicin loop (SRL), ndi peptidyl transferase center (PTC). d Kuchuluka kwa ma electron kofanana ndi pakati pa peptidyl transferase ya E. cuniculi ribosome kukuwonetsa kuti malo ofunikira awa ali ndi kapangidwe komweko mu E. cuniculi parasite ndi omwe ali nawo, kuphatikiza H. sapiens. e, f Kuchuluka kwa ma elekitironi kofanana ndi malo owerengera (e) ndi kapangidwe kake ka malo owerengera (f) zikusonyeza kuti E. cuniculi ili ndi zotsalira za U1491 m'malo mwa A1491 (E. coli numbering) m'ma eukaryotes ena ambiri. Kusinthaku kukusonyeza kuti E. cuniculi ikhoza kukhala yogwirizana ndi maantibayotiki omwe amalimbana ndi malo ogwirira ntchito awa.
Mosiyana ndi kapangidwe ka V. necatrix ndi P. locustae ribosomes (kapangidwe kake konse kakuyimira banja la microsporidia lomwelo la Nosematidae ndipo ndi lofanana kwambiri), 31,32 E. cuniculi ribosomes amadutsa njira zambiri za rRNA ndi kugawikana kwa mapuloteni. Kuwonjezeka kwa mawonekedwe (Zithunzi Zowonjezera 4-6). Mu rRNA, kusintha kwakukulu kunaphatikizapo kutayika kwathunthu kwa chidutswa cha 25S rRNA ES12L chokwezedwa komanso kuwonongeka pang'ono kwa ma helices a h39, h41, ndi H18 (Chithunzi 1c, Chithunzi Chowonjezera 4). Pakati pa mapuloteni a ribosomal, kusintha kwakukulu kunaphatikizapo kutayika kwathunthu kwa mapuloteni a eS30 ndi kufupikitsa mapuloteni a eL8, eL13, eL18, eL22, eL29, eL40, uS3, uS9, uS14, uS17, ndi eS7 (Zithunzi Zowonjezera 4, 5).
Motero, kuchepa kwakukulu kwa majini a mitundu ya Encephalotozoon/Ordospora kumaonekera mu kapangidwe ka ribosome yawo: Ma ribosome a E. cuniculi amakumana ndi kutayika kwakukulu kwa mapuloteni mu ma ribosome a eukaryotic cytoplasmic omwe amakhudzidwa ndi kapangidwe kake, ndipo alibe ngakhale zidutswa za rRNA ndi mapuloteni zomwe zimasungidwa kwambiri osati mu ma eukaryotes okha, komanso m'magawo atatu a moyo. Kapangidwe ka E. cuniculi ribosome kamapereka chitsanzo choyamba cha mamolekyu a kusinthaku ndipo kumavumbula zochitika zosinthika zomwe zanyalanyazidwa ndi majini ofanana ndi maphunziro a kapangidwe ka biomolecular mkati mwa maselo (Chithunzi Chowonjezera 7). Pansipa, tikufotokoza chilichonse mwa zochitikazi pamodzi ndi chiyambi chawo chosinthika komanso momwe chingakhudzire ntchito ya ribosome.
Kenako tinapeza kuti, kuwonjezera pa kudula kwakukulu kwa rRNA, ma ribosome a E. cuniculi ali ndi kusiyana kwa rRNA pamalo awo omwe amagwira ntchito. Ngakhale kuti pakati pa peptidyl transferase pa E. cuniculi ribosome pali kapangidwe kofanana ndi ma ribosome ena a eukaryotic (Chithunzi 1d), malo owerengera amasiyana chifukwa cha kusiyana kwa sequence pa nucleotide 1491 (E. coli numbering, Chithunzi 1e, f). Kuwona kumeneku ndikofunikira chifukwa malo owerengera ma ribosome a eukaryotic nthawi zambiri amakhala ndi zotsalira za G1408 ndi A1491 poyerekeza ndi zotsalira zamtundu wa bakiteriya A1408 ndi G1491. Kusiyana kumeneku kumayambitsa kusiyana kwa ma ribosome a bakiteriya ndi eukaryotic ku banja la aminoglycoside la maantibayotiki a ribosomal ndi mamolekyu ena ang'onoang'ono omwe amalunjika pamalo owerengera. Pamalo olembera E. cuniculi ribosome, zotsalira za A1491 zinasinthidwa ndi U1491, zomwe zingapangitse kuti pakhale mawonekedwe apadera omangira mamolekyu ang'onoang'ono omwe akuyang'ana malo ogwirira ntchito awa. Mtundu womwewo wa A14901 uliponso mu microsporidia zina monga P. locustae ndi V. necatrix, zomwe zikusonyeza kuti ndizofala pakati pa mitundu ya microsporidia (Chithunzi 1f).
Popeza zitsanzo zathu za ribosome ya E. cuniculi zinachotsedwa ku spores zomwe sizigwira ntchito m'thupi, tinayesa mapu a cryo-EM a E. cuniculi kuti tipeze ribosome yolumikizidwa kale pansi pa kupsinjika kapena njala. Zinthu zobisika 31,32,36,37, 38. Tinagwirizanitsa kapangidwe ka ribosome yobisika kale ndi mapu a cryo-EM a E. cuniculi ribosome. Pa docking, ma ribosome a S. cerevisiae adagwiritsidwa ntchito mu complex ndi hibernation factor Stm138, locust ribosomes mu complex ndi Lso232 factor, ndi V. necatrix ribosomes mu complex ndi Mdf1 ndi Mdf231 factors. Nthawi yomweyo, tinapeza kuchuluka kwa cryo-EM komwe kumagwirizana ndi rest factor Mdf1. Mofanana ndi Mdf1 yomangirira ku ribosome ya V. necatrix, Mdf1 imalumikizananso ndi ribosome ya E. cuniculi, komwe imatseka malo a E a ribosome, mwina kuthandiza kuti ma ribosome apezeke pamene ma spores a tizilombo toyambitsa matenda sagwira ntchito m'thupi akasiya kugwira ntchito (Chithunzi 2).
Mdf1 imatseka malo a E a ribosome, zomwe zimawoneka kuti zimathandiza kuletsa ribosome pamene spores za tizilombo toyambitsa matenda sizigwira ntchito bwino. Mu kapangidwe ka E. cuniculi ribosome, tapeza kuti Mdf1 imapanga kukhudzana komwe sikunadziwike kale ndi tsinde la L1 ribosome, gawo la ribosome lomwe limathandizira kutulutsidwa kwa deacylated tRNA kuchokera ku ribosome panthawi yopanga mapuloteni. Kulumikizana kumeneku kukusonyeza kuti Mdf1 imasiyana ndi ribosome pogwiritsa ntchito njira yomweyi monga deacetylated tRNA, zomwe zikupereka kufotokozera momwe ribosome imachotsera Mdf1 kuti iyambitsenso kupanga mapuloteni.
Komabe, kapangidwe kathu kanavumbula kukhudzana kosadziwika pakati pa Mdf1 ndi mwendo wa L1 ribosome (gawo la ribosome lomwe limathandiza kutulutsa deacylated tRNA kuchokera ku ribosome panthawi yopanga mapuloteni). Makamaka, Mdf1 imagwiritsa ntchito kukhudzana komweko ndi gawo la chigongono cha molekyulu ya deacylated tRNA (Chithunzi 2). Chitsanzo cha mamolekyu chomwe sichinadziwike kale chinawonetsa kuti Mdf1 imasiyana ndi ribosome pogwiritsa ntchito njira yomweyi monga deacetylated tRNA, zomwe zimafotokoza momwe ribosome imachotsera hibernation factor iyi kuti iyambitsenso kupanga mapuloteni.
Popanga chitsanzo cha rRNA, tinapeza kuti E. cuniculi ribosome ili ndi zidutswa za rRNA zopindika modabwitsa, zomwe tidazitcha kuti fused rRNA (Chithunzi 3). Mu ma ribosome omwe amadutsa magawo atatu a moyo, rRNA imapindika m'mapangidwe momwe ma rRNA ambiri amakhala maziko awiriawiri ndikupindika wina ndi mnzake kapena kuyanjana ndi mapuloteni a ribosomal38,39,40. Komabe, mu E. cuniculi ribosomes, ma rRNA akuwoneka kuti akuswa mfundo yopindika iyi posintha ma helices awo kukhala madera osatsegulidwa a rRNA.
Kapangidwe ka H18 25S rRNA helix mu S. cerevisiae, V. necatrix, ndi E. cuniculi. Kawirikawiri, mu ma ribosomes omwe ali m'magawo atatu a moyo, linker iyi imazungulira kukhala RNA helix yomwe ili ndi zotsalira 24 mpaka 34. Mu Microsporidia, mosiyana, linker iyi ya rRNA imachepetsedwa pang'onopang'ono kukhala zolumikizira ziwiri zokhala ndi uridine imodzi yokhala ndi zotsalira 12 zokha. Zambiri mwa zotsalirazi zimakumana ndi zosungunulira. Chithunzichi chikuwonetsa kuti microsporidia ya parasitic imawoneka kuti ikuphwanya mfundo zazikulu za kupindika kwa rRNA, komwe maziko a rRNA nthawi zambiri amalumikizidwa ndi maziko ena kapena amachita nawo mgwirizano wa rRNA-protein. Mu microsporidia, zidutswa zina za rRNA zimakhala zopindika zosasangalatsa, momwe helix yakale ya rRNA imakhala chidutswa chopindika chimodzi chotalikitsidwa pafupifupi mzere wowongoka. Kupezeka kwa madera osazolowereka awa kumalola microsporidia rRNA kumangirira zidutswa zakutali za rRNA pogwiritsa ntchito maziko ochepa a RNA.
Chitsanzo chodziwika bwino cha kusinthaku kwa chisinthiko chikuwoneka mu H18 25S rRNA helix (Chithunzi 3). Mu mitundu kuyambira E. coli kupita kwa anthu, maziko a rRNA helix iyi ali ndi ma nucleotide 24-32, omwe amapanga helix yosasinthasintha pang'ono. Mu kapangidwe ka ribosomal komwe kadadziwika kale kuchokera ku V. necatrix ndi P. locustae,31,32 maziko a H18 helix amatsegulidwa pang'ono, koma kuphatikizika kwa maziko a nucleotide kumasungidwa. Komabe, mu E. cuniculi chidutswa ichi cha rRNA chimakhala cholumikizira chachifupi kwambiri 228UUUGU232 ndi 301UUUUUUUUU307. Mosiyana ndi zidutswa za rRNA wamba, ma linker awa okhala ndi uridine sazungulira kapena kukhudzana kwambiri ndi mapuloteni a ribosomal. M'malo mwake, amatenga mapangidwe otseguka komanso otseguka kwathunthu momwe zingwe za rRNA zimatambasulidwira molunjika. Kapangidwe kameneka kakufotokoza momwe E. cuniculi imagwiritsira ntchito maziko 12 a RNA okha kuti adzaze mpata wa 33 Å pakati pa ma helices a H16 ndi H18 rRNA, pomwe mitundu ina imafuna maziko owirikiza kawiri a rRNA kuti adzaze mpatawo.
Motero, tingathe kusonyeza kuti, kudzera mu kupindika kosasangalatsa kwa mphamvu, ma microsporidia a parasitic apanga njira yochepetsera ngakhale magawo a rRNA omwe amasungidwa bwino m'mitundu yonse m'magawo atatu a moyo. Mwachionekere, mwa kusonkhanitsa masinthidwe omwe amasintha ma rRNA helices kukhala ma poly-U linker afupiafupi, E. cuniculi imatha kupanga zidutswa zachilendo za rRNA zokhala ndi ma nucleotide ochepa momwe zingathere kuti amangirire zidutswa za distal rRNA. Izi zimathandiza kufotokoza momwe microsporidia idapezera kuchepa kwakukulu kwa kapangidwe kawo koyambira popanda kutaya kapangidwe kake komanso magwiridwe antchito.
Chinthu china chachilendo cha E. cuniculi rRNA ndi mawonekedwe a rRNA opanda makulidwe (Chithunzi 4). Ma bulges ndi ma nucleotide opanda ma base pairs omwe amapotoka kuchokera ku RNA helix m'malo mobisalamo. Ma protrusions ambiri a rRNA amagwira ntchito ngati ma molecular glue, kuthandiza kumangirira mapuloteni a ribosomal oyandikana nawo kapena zidutswa zina za rRNA. Ma bulges ena amagwira ntchito ngati ma hinges, kulola rRNA helix kusinthasintha ndikupindika bwino kuti mapuloteni apange 41.
Kutuluka kwa rRNA (S. cerevisiae numbering) kulibe mu kapangidwe ka E. cuniculi ribosome, koma kumapezeka mu ma eukaryotes ena ambiri b E. coli, S. cerevisiae, H. sapiens, ndi E. cuniculi internal ribosomes. Majeremusi alibe ma bulges ambiri akale, osungidwa bwino a rRNA. Kukhuthala kumeneku kumalimbitsa kapangidwe ka ribosome; chifukwa chake, kusakhalapo kwawo mu microsporidia kumasonyeza kuchepa kwa kukhazikika kwa rRNA mu majeremusi a microsporidia. Kuyerekeza ndi ma P stems (L7/L12 stems mu mabakiteriya) kukuwonetsa kuti kutayika kwa ma bulges a rRNA nthawi zina kumagwirizana ndi kuwoneka kwa ma bulges atsopano pafupi ndi ma bulges otayika. H42 helix mu 23S/28S rRNA ili ndi bulge yakale (U1206 mu Saccharomyces cerevisiae) yomwe ikuyerekezeredwa kuti ili ndi zaka zosachepera 3.5 biliyoni chifukwa cha chitetezo chake m'magawo atatu a moyo. Mu microsporidia, bulge iyi imachotsedwa. Komabe, chiphuphu chatsopano chinaonekera pafupi ndi chiphuphu chotayika (A1306 mu E. cuniculi).
Chodabwitsa n'chakuti, tinapeza kuti ma ribosome a E. cuniculi alibe ma bulges ambiri a rRNA omwe amapezeka m'mitundu ina, kuphatikizapo ma bulges oposa 30 omwe amasungidwa mu ma eukaryotes ena (Chithunzi 4a). Kutayika kumeneku kumachotsa kulumikizana kwakukulu pakati pa ma subunits a ribosomal ndi ma helices a rRNA oyandikana nawo, nthawi zina kupanga mabowo akuluakulu mkati mwa ribosome, zomwe zimapangitsa kuti E. cuniculi ribosome ikhale ndi mabowo ambiri poyerekeza ndi ma ribosome achikhalidwe (Chithunzi 4b). Chodziwika bwino n'chakuti, tinapeza kuti ma bulges ambiriwa adatayikanso m'mapangidwe a ribosome a V. necatrix ndi P. locustae omwe adadziwika kale, omwe adanyalanyazidwa ndi kusanthula kwa kapangidwe kakale31,32.
Nthawi zina kutayika kwa ma rRNA bulges kumayenderana ndi kupangika kwa ma bulges atsopano pafupi ndi bulge yotayika. Mwachitsanzo, ribosomal P-stem ili ndi bulge ya U1208 (mu Saccharomyces cerevisiae) yomwe idapulumuka kuchokera ku E. coli kupita kwa anthu ndipo motero akuti ili ndi zaka 3.5 biliyoni. Pakupanga mapuloteni, bulge iyi imathandiza tsinde la P kusuntha pakati pa mawonekedwe otseguka ndi otsekedwa kotero kuti ribosome ikhoza kutenga zinthu zosinthira ndikuzipereka kumalo ogwirira ntchito. Mu E. cuniculi ribosomes, kukhuthala kumeneku kulibe; komabe, kukhuthala kwatsopano (G883) komwe kumakhala m'magawo atatu okha kumatha kuthandizira kubwezeretsa kusinthasintha kwabwino kwa tsinde la P (Chithunzi 4c).
Deta yathu pa rRNA yopanda ma bulges ikusonyeza kuti kuchepetsa rRNA sikungokhudza kutayika kwa zinthu za rRNA pamwamba pa ribosome, komanso kungakhudzenso nucleus ya ribosome, zomwe zimapangitsa kuti pakhale vuto la mamolekyulu omwe sanafotokozedwe m'maselo okhala ndi moyo wodziyimira pawokha.
Pambuyo pokonza mapuloteni a ribosomal ovomerezeka ndi rRNA, tinapeza kuti zigawo za ribosomal zodziwika bwino sizingathe kufotokoza magawo atatu a chithunzi cha cryo-EM. Zidutswa ziwirizi ndi mamolekyu ang'onoang'ono kukula kwake (Chithunzi 5, Chithunzi Chowonjezera 8). Gawo loyamba lili pakati pa mapuloteni a ribosomal uL15 ndi eL18 pamalo omwe nthawi zambiri amakhala ndi C-terminus ya eL18, yomwe imafupikitsidwa mu E. cuniculi. Ngakhale sitingathe kudziwa kuti molekyulu iyi ndi yotani, kukula ndi mawonekedwe a chilumbachi chodetsa akufotokozedwa bwino ndi kupezeka kwa mamolekyulu a spermidine. Kulumikizana kwake ndi ribosome kumakhazikika ndi kusintha kwa microsporidia mu mapuloteni a uL15 (Asp51 ndi Arg56), omwe akuwoneka kuti akuwonjezera kuyanjana kwa ribosome kwa molekyulu yaying'ono iyi, chifukwa amalola uL15 kukulunga molekyulu yaying'onoyo kukhala kapangidwe ka ribosomal. Chithunzi Chowonjezera 2). 8, deta yowonjezera 1, 2).
Chithunzi cha Cryo-EM chosonyeza kukhalapo kwa ma nucleotide kunja kwa ribose yolumikizidwa ku ribosome ya E. cuniculi. Mu ribosome ya E. cuniculi, nucleotide iyi ili pamalo omwewo monga 25S rRNA A3186 nucleotide (Saccharomyces cerevisiae numbering) m'ma ribosome ena ambiri a eukaryotic. b Mu kapangidwe ka ribosomal ka E. cuniculi, nucleotide iyi ili pakati pa mapuloteni a ribosomal uL9 ndi eL20, motero imakhazikitsa kukhudzana pakati pa mapuloteni awiriwa. cd eL20 sequence conservation analysis pakati pa mitundu ya microsporidia. Mtengo wa phylogenetic wa mitundu ya Microsporidia (c) ndi kulinganiza kwa mapuloteni ambiri a eL20 (d) zikusonyeza kuti zotsalira zomangira nucleotide F170 ndi K172 zimasungidwa mu Microsporidia yamba, kupatula S. lophii, kupatula Microsporidia yoyambirira ya nthambi, yomwe idasunga kufalikira kwa ES39L rRNA. Chithunzichi chikuwonetsa kuti zotsalira zomangira nucleotide F170 ndi K172 zimapezeka mu eL20 yokha ya genome ya microsporidia yochepetsedwa kwambiri, koma osati mu eukaryotes zina. Ponseponse, deta iyi ikusonyeza kuti Microsporidian ribosomes yapanga malo omangira nucleotide omwe amawoneka kuti amamanga mamolekyu a AMP ndikuzigwiritsa ntchito kukhazikika kwa mgwirizano wa mapuloteni ndi mapuloteni mu kapangidwe ka ribosomal. Kusungidwa kwakukulu kwa malo omangira awa mu Microsporidia ndi kusakhalapo kwake mu eukaryotes zina kukuwonetsa kuti malowa angapereke mwayi wosankha wopulumuka wa Microsporidia. Motero, thumba lomangira nucleotide mu microsporidia ribosome silikuwoneka ngati chinthu chowonongeka kapena mawonekedwe omaliza a kuwonongeka kwa rRNA monga tafotokozera kale, koma ndi njira yothandiza yosinthira yomwe imalola microsporidia ribosome kumangirira mwachindunji mamolekyu ang'onoang'ono, kuwagwiritsa ntchito ngati zomangira mamolekyu. Kupeza kumeneku kumapangitsa microsporidia ribosome kukhala ribosome yokhayo yomwe imadziwika kuti imagwiritsa ntchito nucleotide imodzi ngati chomangira chake. f Njira yongopeka yosinthika yochokera ku kumangira nucleotide.
Kulemera kwachiwiri kwa mamolekyulu otsika kuli pamalo olumikizirana pakati pa mapuloteni a ribosomal uL9 ndi eL30 (Chithunzi 5a). Malo olumikiziranawa adafotokozedwa kale mu kapangidwe ka Saccharomyces cerevisiae ribosome ngati malo omangirira a 25S nucleotide ya rRNA A3186 (gawo la ES39L rRNA extension)38. Zawonetsedwa kuti mu ma ribosome a P. locustae ES39L ofooka, malo olumikiziranawa amamanga nucleotide imodzi yosadziwika 31, ndipo akuganiziridwa kuti nucleotide iyi ndi mtundu womaliza wa rRNA wochepetsedwa, momwe kutalika kwa rRNA kuli ~130-230 bases. ES39L imachepetsedwa kukhala nucleotide imodzi 32.43. Zithunzi zathu za cryo-EM zimathandizira lingaliro lakuti kuchulukana kumatha kufotokozedwa ndi nucleotides. Komabe, mawonekedwe apamwamba a kapangidwe kathu adawonetsa kuti nucleotide iyi ndi molekyulu ya extraribosomal, mwina AMP (Chithunzi 5a, b).
Kenako tinafunsa ngati malo omangira nucleotide adawonekera mu E. cuniculi ribosome kapena ngati analipo kale. Popeza kumangira nucleotide kumachitika makamaka ndi zotsalira za Phe170 ndi Lys172 mu puloteni ya eL30 ribosomal, tinayesa kusungidwa kwa zotsalira izi mu ma eukaryotes 4396 oimira. Monga momwe zinalili ndi uL15 pamwambapa, tapeza kuti zotsalira za Phe170 ndi Lys172 zimasungidwa kwambiri mu Microsporidia wamba, koma sizipezeka mu ma eukaryotes ena, kuphatikiza atypical Microsporidia Mitosporidium ndi Amphiamblys, momwe chidutswa cha ES39L rRNA sichimachepetsedwa 44, 45, 46 (Chithunzi 5c). -e).
Ponseponse, deta iyi ikuchirikiza lingaliro lakuti E. cuniculi ndi mwina ma microsporidia ena ovomerezeka apanga luso logwira bwino ma metabolites ang'onoang'ono ambiri mu kapangidwe ka ribosome kuti athandizire kuchepa kwa rRNA ndi mapuloteni. Pochita izi, apanga luso lapadera lomangirira ma nucleotide kunja kwa ribosome, kusonyeza kuti mapangidwe a mamolekyu a parasitic amathandizanso pogwira ma metabolites ang'onoang'ono ambiri ndikuwagwiritsa ntchito ngati zofananira za RNA ndi zidutswa za mapuloteni zomwe zawonongeka.
Gawo lachitatu losayerekezeka la mapu athu a cryo-EM, lomwe limapezeka mu gawo lalikulu la ribosomal. Kuchuluka kwapamwamba (2.6 Å) kwa mapu athu kukusonyeza kuti kuchulukana kumeneku ndi kwa mapuloteni okhala ndi mitundu yapadera ya zotsalira zazikulu za unyolo, zomwe zinatilola kuzindikira kuchulukana kumeneku ngati puloteni ya ribosomal yomwe sitinaidziwe kale yomwe tidaizindikira kuti idatchedwa msL2 (Microsporidia- specific protein L2) (njira, chithunzi 6). Kufufuza kwathu kwa homology kunawonetsa kuti msL2 imasungidwa mu Microsporidia clade ya mtundu wa Encephaliter ndi Orosporidium, koma palibe m'mitundu ina, kuphatikiza Microsporidia ina. Mu kapangidwe ka ribosomal, msL2 imakhala ndi mpata womwe umapangidwa ndi kutayika kwa ES31L rRNA yotambasuka. Mu void iyi, msL2 imathandizira kukhazikika kwa rRNA ndipo imatha kulipira kutayika kwa ES31L (Chithunzi 6).
Kuchuluka kwa ma elekitironi ndi chitsanzo cha puloteni ya ribosomal ya Microsporidia yomwe imapezeka mu E. cuniculi ribosomes. b Ma ribosome ambiri a eukaryotic, kuphatikiza 80S ribosome ya Saccharomyces cerevisiae, ali ndi ES19L rRNA amplification yotayika mu mitundu yambiri ya Microsporidian. Kapangidwe ka V. necatrix microsporidia ribosome komwe kanakhazikitsidwa kale kakusonyeza kuti kutayika kwa ES19L m'majeremusi awa kumalipidwa ndi kusintha kwa puloteni yatsopano ya msL1 ribosomal. Mu kafukufukuyu, tapeza kuti E. cuniculi ribosome idapanganso puloteni yowonjezera ya ribosomal RNA ngati chiwongola dzanja chowonekera cha kutayika kwa ES19L. Komabe, msL2 (yomwe pakadali pano imatchulidwa kuti puloteni ya ECU06_1135) ndi msL1 zili ndi magwero osiyanasiyana a kapangidwe ndi kusintha. Kupezeka kumeneku kwa kupanga mapuloteni a ribosomal a msL1 ndi msL2 osagwirizana ndi kusintha kwa zinthu kukusonyeza kuti ngati ma ribosome asonkhanitsa masinthidwe oipa mu rRNA yawo, amatha kukwaniritsa mitundu yosiyanasiyana ya kapangidwe kake ngakhale m'gulu laling'ono la mitundu yofanana kwambiri. Kupezeka kumeneku kungathandize kufotokoza bwino chiyambi ndi kusintha kwa mitochondrial ribosome, yomwe imadziwika ndi kuchepa kwake kwa rRNA komanso kusiyana kosazolowereka kwa kapangidwe ka mapuloteni pamitundu yonse.
Kenako tinayerekeza puloteni ya msL2 ndi puloteni ya msL1 yomwe yafotokozedwa kale, puloteni yokhayo yodziwika bwino ya microsporidia yomwe imapezeka mu V. necatrix ribosome. Tinkafuna kuyesa ngati msL1 ndi msL2 zimagwirizana ndi kusintha kwa zinthu. Kusanthula kwathu kunawonetsa kuti msL1 ndi msL2 zili m'chibowo chomwecho mu kapangidwe ka ribosomal, koma zili ndi kapangidwe kosiyana koyambirira ndi kachitatu, zomwe zikusonyeza kuti zimachokera pakusintha kwa zinthu (Chithunzi 6). Chifukwa chake, kupeza kwathu msL2 kumapereka umboni wakuti magulu a mitundu yaying'ono ya eukaryotic amatha kusintha mapuloteni a ribosomal kuti akwaniritse kutayika kwa zidutswa za rRNA. Kupeza kumeneku kumadziwika bwino chifukwa chakuti ma ribosome ambiri a cytoplasmic eukaryotic ali ndi puloteni yosasinthika, kuphatikiza banja lomwelo la mapuloteni 81 a ribosomal. Kuwoneka kwa msL1 ndi msL2 m'magulu osiyanasiyana a microsporidia poyankha kutayika kwa magawo owonjezera a rRNA kukuwonetsa kuti kuwonongeka kwa kapangidwe ka maselo a tizilombo toyambitsa matenda kumapangitsa kuti tizilombo toyambitsa matenda tifune kusintha kwa zinthu, zomwe pamapeto pake zingayambitse kupezeka kwawo m'magulu osiyanasiyana a tizilombo toyambitsa matenda.
Pomaliza, pamene chitsanzo chathu chinamalizidwa, tinayerekeza kapangidwe ka ribosome ya E. cuniculi ndi yomwe inanenedweratu kuchokera ku genome sequence. Mapuloteni angapo a ribosomal, kuphatikizapo eL14, eL38, eL41, ndi eS30, kale ankaganiziridwa kuti akusowa mu genome ya E. cuniculi chifukwa cha kusakhalapo kwa ma homologues awo kuchokera ku genome ya E. cuniculi. Kutayika kwa mapuloteni ambiri a ribosomal kumanenedweratunso m'ma parasites ena ambiri omwe ali ndi ma endosymbionts ochepa kwambiri mkati mwa maselo. Mwachitsanzo, ngakhale kuti mabakiteriya ambiri okhala ndi moyo ali ndi banja lomwelo la mapuloteni 54 a ribosomal, mabanja 11 okha a mapuloteni awa ali ndi ma homologues omwe amawonedwa mu genome iliyonse yowunikidwa ya mabakiteriya oletsedwa ndi wolandira. Pothandizira lingaliro ili, kutayika kwa mapuloteni a ribosomal kwawonedwa mwa kuyesa mu V. necatrix ndi P. locustae microsporidia, omwe alibe mapuloteni a eL38 ndi eL4131,32.
Komabe, kapangidwe kathu kakusonyeza kuti eL38, eL41, ndi eS30 zokha ndi zomwe zimatayika mu E. cuniculi ribosome. Puloteni ya eL14 idasungidwa ndipo kapangidwe kathu kawonetsa chifukwa chake puloteni iyi sinapezeke mu kufufuza kwa homology (Chithunzi 7). Mu E. cuniculi ribosomes, malo ambiri omangira a eL14 amatayika chifukwa cha kuwonongeka kwa rRNA-amplified ES39L. Popanda ES39L, eL14 idataya kapangidwe kake kachiwiri, ndipo 18% yokha ya mndandanda wa eL14 inali yofanana mu E. cuniculi ndi S. cerevisiae. Kusungidwa kosauka kwa mndandandawu n'kodabwitsa chifukwa ngakhale Saccharomyces cerevisiae ndi Homo sapiens—zamoyo zomwe zidasanduka zaka 1.5 biliyoni—zimagawana zotsalira zoposa 51% zomwezo mu eL14. Kutayika kwachilendo kumeneku kwa kusungidwa kukufotokoza chifukwa chake E. cuniculi eL14 pakadali pano ikufotokozedwa ngati puloteni ya M970_061160 osati ngati puloteni ya eL1427 ribosomal.
ndipo Microsporidia ribosome inataya ES39L rRNA extension, yomwe inachotsa pang'ono malo omangira mapuloteni a eL14 ribosomal. Popanda ES39L, puloteni ya microspore ya eL14 imataya kapangidwe kake kachiwiri, momwe α-helix yomangira rRNA yakale imasokonekera kukhala loop yocheperako. b Kulinganiza kwa ma sequence angapo kumasonyeza kuti puloteni ya eL14 imasungidwa kwambiri mu mitundu ya eukaryotic (57% sequence identification pakati pa yisiti ndi ma homologues a anthu), koma imasungidwa bwino komanso yosiyana mu microsporidia (momwe palibe zotsalira zoposa 24% zomwe zili zofanana ndi eL14 homologue). kuchokera ku S. cerevisiae kapena H. sapiens). Kusasunga bwino kwa ma sequence ndi kusintha kwa kapangidwe kake kachiwiri kukufotokoza chifukwa chake eL14 homologue sinapezekepo mu E. cuniculi ndi chifukwa chake puloteni iyi imaganiziridwa kuti yatayika mu E. cuniculi. Mosiyana ndi zimenezi, E. cuniculi eL14 inalembedwa kale ngati puloteni ya M970_061160. Izi zikusonyeza kuti kusiyanasiyana kwa majini a microsporidia pakadali pano kukuyerekezeredwa mopitirira muyeso: majini ena omwe akuganiziridwa kuti atayika mu microsporidia kwenikweni asungidwa, ngakhale m'njira zosiyanasiyana kwambiri; m'malo mwake, ena akuganiziridwa kuti amalemba majini a microsporidia a mapuloteni enieni a nyongolotsi (monga, puloteni yongopeka ya M970_061160) kwenikweni amalemba mapuloteni osiyanasiyana omwe amapezeka mu eukaryotes zina.
Kupeza kumeneku kukusonyeza kuti kusintha kwa rRNA kungayambitse kutayika kwakukulu kwa kusungidwa kwa ma protein a ribosomal omwe ali pafupi, zomwe zimapangitsa kuti mapuloteniwa asawonekere kuti afufuzidwe mofanana. Chifukwa chake, tingayerekezere mopitirira muyeso kuchuluka kwenikweni kwa kuwonongeka kwa mamolekyu m'zamoyo zazing'ono za genome, popeza mapuloteni ena omwe amaganiziridwa kuti atayika amapitilirabe, ngakhale m'mitundu yosinthika kwambiri.
Kodi tizilombo toyambitsa matenda tingapitirize bwanji kugwira ntchito kwa makina awo a mamolekyulu pamene majini awo akuchepa kwambiri? Kafukufuku wathu akuyankha funsoli pofotokoza kapangidwe ka mamolekyulu ovuta (ribosome) a E. cuniculi, chamoyo chokhala ndi majini ang'onoang'ono kwambiri a eukaryotic.
Kwa zaka pafupifupi makumi awiri zakhala zikudziwika kuti mamolekyu a mapuloteni ndi RNA m'majeremusi a tizilombo toyambitsa matenda nthawi zambiri amasiyana ndi mamolekyu awo ofanana m'mitundu yamoyo chifukwa alibe malo owongolera khalidwe, amachepetsedwa kufika pa 50% ya kukula kwawo m'majeremusi okhala ndi moyo, ndi zina zotero. kusintha kwakukulu komwe kumalepheretsa kupindika ndi kugwira ntchito. Mwachitsanzo, ma ribosome a zamoyo zazing'ono za genome, kuphatikizapo majeremusi ambiri amkati mwa maselo ndi ma endosymbionts, akuyembekezeka kusowa mapuloteni angapo a ribosomal ndi mpaka gawo limodzi mwa magawo atatu a ma nucleotide a rRNA poyerekeza ndi mitundu yamoyo yokhala ndi moyo 27, 29, 30, 49. Komabe, momwe mamolekyu awa amagwirira ntchito m'majeremusi akadali chinsinsi, chomwe chimaphunziridwa makamaka kudzera mu ma genomics ofanana.
Kafukufuku wathu akuwonetsa kuti kapangidwe ka macromolecules kangavumbule mbali zambiri za chisinthiko zomwe zimakhala zovuta kuzichotsa kuchokera ku maphunziro achikhalidwe oyerekeza majini a tizilombo toyambitsa matenda mkati mwa maselo ndi zamoyo zina zomwe sizili ndi mphamvu (Chithunzi Chowonjezera 7). Mwachitsanzo, chitsanzo cha puloteni ya eL14 chikuwonetsa kuti tingathe kuwerengera mopitirira muyeso kuchuluka kwenikweni kwa kuwonongeka kwa chipangizo cha mamolekyu m'mitundu ya tizilombo toyambitsa matenda. Tizilombo toyambitsa matenda tsopano tikukhulupirira kuti tili ndi majini mazana ambiri a microsporidia. Komabe, zotsatira zathu zikuwonetsa kuti majini ena omwe amawoneka ngati enieni ndi mitundu yosiyana kwambiri ya majini omwe amapezeka m'ma eukaryotes ena. Kuphatikiza apo, chitsanzo cha puloteni ya msL2 chikuwonetsa momwe timanyalanyaza mapuloteni atsopano a ribosomal ndikuchepetsa kuchuluka kwa makina a mamolekyu a tizilombo toyambitsa matenda. Chitsanzo cha mamolekyu ang'onoang'ono chikuwonetsa momwe tinganyalanyazire zatsopano kwambiri m'mapangidwe a mamolekyu a tizilombo omwe angawapatse ntchito yatsopano ya zamoyo.
Poganizira zonsezi, zotsatira zake zimatithandiza kumvetsetsa kusiyana pakati pa kapangidwe ka mamolekyu a zamoyo zomwe zimaletsedwa ndi zinthu zina zomwe zili m'zamoyo zokhala ndi moyo wodziyimira pawokha. Tikuwonetsa kuti makina a mamolekyu, omwe kwa nthawi yayitali amaganiza kuti achepetsedwa, amawonongeka, ndipo amakumana ndi kusintha kosiyanasiyana kofooketsa, m'malo mwake ali ndi mawonekedwe osazolowereka omwe amanyalanyazidwa mwadongosolo.
Kumbali inayi, zidutswa za rRNA zosalimba komanso zidutswa zosakanikirana zomwe tidapeza mu ribosomes ya E. cuniculi zikusonyeza kuti kuchepetsa majini kungasinthe ngakhale magawo a makina oyambira a mamolekyu omwe amasungidwa m'magawo atatu a moyo - patatha zaka pafupifupi 3.5 biliyoni.
Zidutswa za rRNA zopanda bulge komanso zosakanikirana mu E. cuniculi ribosomes ndizofunikira kwambiri poyerekeza ndi kafukufuku wakale wa mamolekyu a RNA mu mabakiteriya a endosymbiotic. Mwachitsanzo, mu aphid endosymbiont Buchnera aphidicola, mamolekyu a rRNA ndi tRNA awonetsedwa kuti ali ndi kapangidwe kogwirizana ndi kutentha chifukwa cha kusagwirizana kwa kapangidwe ka A+T komanso kuchuluka kwakukulu kwa ma base pairs osavomerezeka20,50. Kusintha kumeneku mu RNA, komanso kusintha kwa mamolekyu a mapuloteni, tsopano akuganiziridwa kuti ndi komwe kumayambitsa kudalira kwambiri kwa ma endosymbiont pa ogwirizana nawo komanso kulephera kwa ma endosymbiont kusamutsa kutentha 21, 23. Ngakhale kuti parasitic microsporidia rRNA ili ndi kusintha kosiyana kwa kapangidwe kake, mtundu wa kusinthaku ukusonyeza kuti kuchepa kwa kukhazikika kwa kutentha komanso kudalira kwambiri mapuloteni a chaperone kungakhale zinthu zodziwika bwino za mamolekyu a RNA m'zamoyo zomwe zili ndi majini ochepa.
Kumbali inayi, kapangidwe kathu kakusonyeza kuti tizilombo toyambitsa matenda ta microsporidia tapanga luso lapadera lolimbana ndi zidutswa za rRNA ndi mapuloteni zomwe zasungidwa bwino, zomwe zimapangitsa kuti tigwiritse ntchito zinthu zazing'ono zomwe zimapezeka mosavuta monga zofananira ndi zidutswa za rRNA ndi mapuloteni omwe awonongeka. Kuwonongeka kwa kapangidwe ka mamolekyulu. . Lingaliro ili likuthandizidwa ndi mfundo yakuti mamolekyulu ang'onoang'ono omwe amalipira kutayika kwa zidutswa za mapuloteni mu rRNA ndi ribosomes za E. cuniculi amamangirira ku zotsalira za microsporidia mu mapuloteni a uL15 ndi eL30. Izi zikusonyeza kuti kumangirira mamolekyulu ang'onoang'ono ku ribosomes kungakhale chifukwa cha kusankha bwino, momwe kusintha kwa Microsporidia mu mapuloteni a ribosomal kwasankhidwa chifukwa cha kuthekera kwawo kuwonjezera kuyanjana kwa ribosomes ndi mamolekyulu ang'onoang'ono, zomwe zingayambitse zamoyo za ribosomal zogwira mtima kwambiri. Kupeza kumeneku kukuwulula luso lanzeru mu kapangidwe ka mamolekyulu a tizilombo toyambitsa matenda ndipo kumatipatsa kumvetsetsa bwino momwe mapangidwe a mamolekyu a tizilombo toyambitsa matenda amasungira ntchito yawo ngakhale kusintha kocheperako.
Pakadali pano, kuzindikira mamolekyu ang'onoang'ono awa sikukudziwika bwino. Sizikudziwika bwino chifukwa chake mawonekedwe a mamolekyu ang'onoang'ono awa mu kapangidwe ka ribosomal amasiyana pakati pa mitundu ya microsporidia. Makamaka, sizikudziwika bwino chifukwa chake kulumikizana kwa nucleotide kumawonedwa mu ribosomes ya E. cuniculi ndi P. locustae, osati mu ribosomes ya V. necatrix, ngakhale kuti pali zotsalira za F170 mu mapuloteni a eL20 ndi K172 a V. necatrix. Kuchotsedwa kumeneku kungayambitsidwe ndi zotsalira 43 uL6 (zomwe zili pafupi ndi thumba lomangira nucleotide), lomwe ndi tyrosine mu V. necatrix osati threonine mu E. cuniculi ndi P. locustae. Unyolo waukulu wa mbali ya aromatic wa Tyr43 ukhoza kusokoneza kulumikizana kwa nucleotide chifukwa cha steric overlap. Kapenanso, kuchotsedwa kwa nucleotide komwe kumawoneka kungakhale chifukwa cha kusasinthika kochepa kwa cryo-EM imaging, komwe kumalepheretsa kupanga mapangidwe a zidutswa za ribosomal za V. necatrix.
Kumbali ina, ntchito yathu ikusonyeza kuti njira yowola majini ikhoza kukhala mphamvu yopangidwa. Makamaka, kapangidwe ka E. cuniculi ribosome kakusonyeza kuti kutayika kwa rRNA ndi zidutswa za mapuloteni mu microsporidia ribosome kumapanga mphamvu yosinthika yomwe imalimbikitsa kusintha kwa kapangidwe ka ribosome. Mitundu iyi imachitika kutali ndi malo ogwirira ntchito a ribosome ndipo ikuwoneka kuti imathandizira kusunga (kapena kubwezeretsa) kusonkhana kwabwino kwa ribosome komwe kukanasokonezedwa ndi rRNA yocheperako. Izi zikusonyeza kuti kupangidwa kwakukulu kwa microsporidia ribosome kukuwoneka kuti kwasintha kukhala kufunika koletsa kusuntha kwa majini.
Mwina izi zikufotokozedwa bwino ndi kumangidwa kwa nucleotide, komwe sikunaonekepo m'zamoyo zina mpaka pano. Mfundo yakuti zotsalira za nucleotide-binding zimapezeka mu microsporidia wamba, koma osati mu eukaryotes zina, ikusonyeza kuti malo omangidwa ndi nucleotide si zinthu zotsalira zomwe zimangoyembekezera kuzimiririka, kapena malo omaliza a rRNA kuti abwezeretsedwe kukhala mawonekedwe a nucleotide payekha. M'malo mwake, malo awa akuwoneka ngati chinthu chothandiza chomwe chikanatha kusintha pakatha ma round angapo a kusankha kwabwino. Malo omangidwa ndi nucleotide akhoza kukhala chifukwa cha kusankha kwachilengedwe: ES39L ikawonongeka, microsporidia amakakamizika kufunafuna ndalama kuti abwezeretse biogenesis yabwino ya ribosome popanda ES39L. Popeza nucleotide iyi imatha kutsanzira kulumikizana kwa mamolekyu a A3186 nucleotide mu ES39L, molekyulu ya nucleotide imakhala chipika chomangira ribosome, chomwe chimamangirira chimawongoleredwa ndi kusintha kwa eL30 sequence.
Ponena za kusintha kwa mamolekyulu a tizilombo toyambitsa matenda m'kati mwa maselo, kafukufuku wathu akusonyeza kuti mphamvu za kusankha kwachilengedwe kwa Darwin ndi kusintha kwa majini kwa kuwonongeka kwa majini sizigwira ntchito nthawi imodzi, koma zimasinthasintha. Choyamba, kusintha kwa majini kumachotsa zinthu zofunika kwambiri za ma biomolecule, zomwe zimapangitsa kuti chiwongola dzanja chikhale chofunikira kwambiri. Pokhapokha ngati tizilombo takwaniritsa zosowa izi kudzera mu kusankha kwachilengedwe kwa Darwin ndi pomwe ma macromolecule awo adzapeza mwayi wopanga makhalidwe awo odabwitsa komanso atsopano. Chofunika kwambiri, kusintha kwa malo omangira nucleotide mu E. cuniculi ribosome kukusonyeza kuti njira iyi yopezera kusintha kwa mamolekyu sikuti imangochepetsa kusintha kwa zinthu, koma nthawi zina imapereka ntchito zatsopano pa ma parasitic macromolecules.
Lingaliro ili likugwirizana ndi chiphunzitso cha Sewell Wright chokhudza kusinthasintha kwa zinthu, chomwe chimati njira yokhwima yosankha zachilengedwe imaletsa kuthekera kwa zamoyo kupanga zatsopano51,52,53. Komabe, ngati kusintha kwa majini kusokoneza kusankha kwachilengedwe, kusinthaku kumatha kupanga kusintha komwe sikungosintha (kapena kovulaza) koma kumabweretsa kusintha kwina komwe kumapereka thanzi labwino kapena ntchito yatsopano ya zamoyo. Dongosolo lathu limachirikiza lingaliro ili posonyeza kuti mtundu womwewo wa kusintha komwe kumachepetsa kupindika ndi kugwira ntchito kwa biomolecule kumawoneka ngati chifukwa chachikulu cha kusintha kwake. Mogwirizana ndi chitsanzo cha kusintha kwa win-win, kafukufuku wathu akuwonetsa kuti kuwonongeka kwa majini, komwe nthawi zambiri kumawonedwa ngati njira yowononga, ndiyenso chinthu chachikulu chomwe chimayambitsa zatsopano, nthawi zina ndipo mwina nthawi zambiri kumalola macromolecules kupeza zochita zatsopano za parasitic.