Aliyense amene amaphunzira zamoyo, sayansi, kukonza majini, ndi chiwerengero cha nzeru zina, posapita nthawi, akufunsa funso: kodi ntchito ya RNA polymerase? Iyi ndi nkhani mwachilungamo zovuta kuti akadali unexplored kwathunthu, koma, koma amadziwika kuti akhale anayatsa monga gawo la nkhani.
zambiri
M'pofunika kumbukirani kuti pali RNA polymerase wa eukaryotes ndi prokaryotes. Woyamba zina ogaŵikana mitundu itatu, omwe ndi amene galamafoniyo imene imachititsa osiyana gulu. michere awa kuchuluka ophweka, pamene woyamba, wachiwiri ndi wachitatu RNA polymerase. Prokaryotes, dongosolo limene sanali nyukiliya, pamene wolembedwa ukugwira ntchito molingana ndi chithunzi m'Chingelezi chosavuta. Choncho, chifukwa ndi losavuta kumva, analanda zambiri monga mmene eukaryotes zotheka lidzachitiridwa. RNA polymerases ndi amapanga ofanana. Akukhulupirira kuti muli osachepera 10 polypeptide unyolo. Choncho RNA polymerase synthesizes 1 (transcribes) majini amene kenako ikumasuliridwa mapuloteni zosiyanasiyana. The chachiwiri chinkhoswe transcribing majini, amene kenako ikumasuliridwa mapuloteni. RNA polymerase 3 amasonyeza khola otsika kulemera michere zosiyanasiyana maselo kuti ali tcheru amtengo kuti Alpha amatinu. Koma ife tiribe anaganiza zimene kwenikweni RNA polymerase! Chotero anaitana michere kuti zikugwira kaphatikizidwe mamolekyulu ribonucleic acid. M'njira yopapatiza bwino kwa izi DNA amadalira RNA polymerase, amene ntchito pa maziko a masanjidwewo asidi deoxyribonucleic. Michere zofunika yaitali ndi bwino kugwira ntchito zamoyo. RNA polymerase angapezeke mu maselo onse ndi mavairasi ambiri.
Kudulidwa pa mfundo za
Malinga ndi kagawo kakang'ono zikuchokera polymerases RNA anawagawa m'magulu awiri:
- The amachita poyamba ndi transcribing ochepa majini mu genomes wa yosavuta. Chifukwa ntchito mu nkhani iyi sikutanthauza zovuta zolimbana amadza. Choncho, apa akunena kuti michere zonse zigwirizana kagawo kakang'ono kamodzi kokha. Mwachitsanzo mukhoza kupangira bacteriophage RNA polymerase ndi mitochondria.
- gulu Izi zikuphatikizapo onse eukaryotic RNA polymerase ndi mabakiteriya, amene ali ovuta anakonza. Iwo zosamvetsetseka mnogosubedinichnye mapuloteni maofesi kuti akhoza transcribe zikwi majini osiyanasiyana. Pa ntchito, majini izi kuyankha ambiri chizindikiro zolimbana amene analandira kwa zinthu mapuloteni ndi nucleotides.
Chotero structural ndi zinchito magawano ndi m'malo makonzedwe ndi zosabvuta pa zinthu zenizeni.
Kodi lemba la RNA polymerase Ine?
Iwo anali atathana ntchito ya maphunziro a zolemba yaikulu ya rRNA majini, ndiko kuti, ndi zofunika kwambiri. Yotsirizira ndi zambiri amadziwika pansi pa chikhazikitso cha 45S-RNA. kutalika ndi pafupifupi 13 000 nucleotides. Kwa izo anapanga 28S-RNA, 18S-5.8S RNA-RNA. Chifukwa chakuti iwo analengedwa yekha transkriptor chimodzi, thupi amalandira "chitsimikizo" kuti mamolekyulu adzakhala anapanga ndalama ofanana. Pa nthawi yomweyo chilengedwe cha RNA mwachindunji amapita nucleotides 7000 chokha. Onse a mawu olembedwa ndi adzitsitsa mu phata la. Anthu a zotsalira lalikulu amakhulupirira kuti m'pofunika kuti magawo oyambirira mapangidwe ribosomes. Chiwerengero cha polymerases izi maselo a anthu apamwamba zikuuluka kuzungulira chizindikiro mayunitsi 40 chikwi.
Mmene zinthu mwadongosolo?
Choncho, tili woyamba RNA polymerase (prokaryotes-dongosolo mamolekyulu) imatengedwa wabwino. Mu nkhani iyi, kagawo kakang'ono lalikulu, Ndithudi, ndipo ambiri zina polypeptides mkulu maselo kulemera, pali bwino distinguishable zinchito ndi structural madambwe. Pa cloning imene imachititsa ndi kudziwa kapangidwe yaikulu akhala amadziŵika ndi asayansi evolutionarily kokhazikika mbali unyolo. Kugwiritsa ntchito mawu abwino ofufuza anali imachitika kusanthula mutational kuti amatilola kulankhula za tanthauzo zinchito za madambwe payekha. Chifukwa chaichi, ntchito malo lotsogozedwa mutagenesis kusintha unyolo polypeptide aliyense, ndipo ngati subunits asidi kusinthidwa kwa amino ntchito mu msonkhano wa michere ndi kusanthula wotsatira wa katundu, zomwe zimapezeka mu nyumba deta. Ananena kuti, chifukwa chipembedzo chake cha woyamba RNA polymerase pamaso pa alpha-amatina (a chinthu kwambiri poizoni, amene analandira kuchokera toadstool wotumbululuka) Kodi samva.
uziyenda
Onse woyamba ndi wachiwiri RNA polymerase angathe kukhala m'njira ziwiri. Mmodzi wa iwo akhoza kuchita kwa kuyambitsa galamafoniyo yeniyeni. The chachiwiri - ndi DNA amadalira RNA polymerase. maganizo amenewa amasonyeza ntchito yaikulu ya ntchito. Mutu anaphunzira zambiri, koma tsopano ife tikudziwa kuti kumatengera zifukwa galamafoniyo awiri, omwe amatchedwa SL1 ndi UBF. Maka comaliza - kuti angathe kulankhula ndi kulimbikitsa, pamene SL1 UBF amafuna kukhalapo. Ngakhale wakhala experimentally anakhazikitsa kuti DNA amadalira RNA polymerase akhoza nawo galamafoniyo pa osachepera ndipo popanda pamaso pa masika. Koma kugwira ntchito za masiku onse limagwirira izi UBF akadali zofunika. N'chifukwa chiyani tikutero? N'zochititsa chidwi mpaka analephera kukhazikitsa chifukwa cha zinthu zimenezi. Wina mafotokozedwe a otchuka zikusonyeza kuti UBF imalimbikitsa ngati stimulant rDNA galamafoniyo pamene iye amalima ndipo akufotokozera. Pamene akupuma gawo zikachitika, ndiye anakhalabe osachepera chofunika mlingo wa chamoyo. A mbali ya zinthu galamafoniyo si yovuta kwa iye. Apa kotero ntchito RNA polymerase. Ntchito enzyme izi zimathandiza kuthandiza kubwezeretsa ochepa "nyumba zingatipunthwitse" za thupi, chifukwa chimene nthawi zonse kusinthidwa kwa zaka zambiri.
Gulu lachiwiri la michere
kugwira ntchito kwawo ndi Lamulo khamu la multiprotein ochirikiza zovuta preinitsiatornogo a kalasi wachiwiri. Nthawi zambiri imeneyi yafotokozedwera ntchito ya mapuloteni wapadera - activators. Chitsanzo ndi TBP. Iwo amagwirizana zinthu zomwe ndi gawo la TFIID. Iwo - chandamale cha p53, NF kappa B, ndi zina zotero. Kukopa kwake mu ndondomeko ya malamulo ndi kupereka mapuloteni otchedwa coactivators. Zitsanzo ndi Gcn5. N'chifukwa chiyani tiyenera mapuloteni izi? Iwo amatumikira adaputala azamagetsi kuti ikonza mogwirizana kwa activators ndi zinthu zina zimene mu preinitsiatorny zovuta. Pofuna kukonza galamafoniyo zinachitika, muyenera kukhala zofunika E zinthu. Ngakhale kuti asanu ndi limodzi, mwachindunji kucheza ndi kulimbikitsa mwina yekha. Pakuti Nthawi zina pamafunika preformed zovuta kwa wachiwiri RNA polymerase. Komanso, nthaŵi awa ali pafupi proximal zinthu - awiriawiri 50-200 okha ku malo galamafoniyo ali anayamba. Iwo ali limasonyeza kumanga mapulotini activator.
wonena za
Kodi kagawo kakang'ono Kapangidwe ka michere chiyambi osiyana pa udindo wawo zinchito mu galamafoniyo chiyani? Yankho lenileni ndi lakuti ayi, koma ankakhulupirira kuti zikuoneka positive. Kodi zingamvekere RNA polymerase? ntchito puloteni losavuta kapangidwe - osiyanasiyana zochepa galamafoniyo imene imachititsa (kapena mbali yaing'ono). Zitsanzo ndi kaphatikizidwe RNA primers Okazaki zidutswa. Amalimbikitsa kulunjika kwa RNA polymerases mabakiteriya ndi phages ndi michere ndi zopalira dongosolo yosavuta ndi osiyanasiyana. Tingaone zimenezi mu ndondomeko ya DNA kugawanika akanika. Ngakhale kuti sitingathe Nganizilani ichi: zovuta dongosolo pamene anaphunzira matupi athu T ngakhale phage, pa chitukuko, izo inafotokoza kuti mobwerezabwereza kusintha pakati pa magulu osiyanasiyana jini galamafoniyo, chinapezeka kuti zovuta ntchito imeneyi khamu RNA polymerase. Ndiye kuti, ndi puloteni kumodzi Zikatero si anachititsa. Izi zikutanthauza zingapo zotsatira:
- RNA polymerase wa eukaryotes ndi mabakiteriya ayenera kuzindikira ochirikiza osiyana.
- M'pofunika kuti enzyme ali ndi yankho yeniyeni osiyana mapuloteni-owongolera.
- RNA polymerase ayenera angathe kusintha kuzindikira kuti kulunjika kwa Chinsinsi DNA nyukiliotayidi zinayendera. Kuchita izi, ntchito zosiyanasiyana effectors mapuloteni.
Ndizoonekeratu kufunika thupi kwa zina "nyumba" zinthu. Mapuloteni kuthandiza transcribe zovuta za RNA polymerase kuti athe kugwira bwino ntchito zake. Zimenezi zikugwira ntchito yaikulu, ndi michere zovuta dongosolo, imene mwayi wa ntchito pulogalamu kwambiri mfundo chibadwa. Chifukwa mavuto osiyanasiyana, ife angaone ngati dongosolo utsogoleri wolowezana wa RNA polymerase.
Kodi ndondomeko ya galamafoniyo?
Kodi pali jini udindo mgwirizano ndi RNA polymerase? Kuyamba wa galamafoniyo: ndondomeko mu eukaryotes chikuchitika mu phata la. Mu prokaryotes, wasefukira mkati bakiteriya a. Kubverana polymerase ndi mfundo structural mfundo za wowonjezera mamolekyulu mating payekha. Pa nkhani ya mogwirizana anganene kuti DNA chabe Chinsinsi ndipo sasintha pa galamafoniyo. Popeza DNA ndi puloteni kwathunthu, chinthu ndi ena, kuti losokonekera makamaka ndi udindo polima zingakhale, koma idzakhala nthawi yaitali kwambiri. Tisaiwale kuti DNA muli biliyoni 3.1 nyukiliotayidi zatsalira. Choncho, m'pofunika kwambiri kunena kuti pa mtundu wa RNA akukumana DNA ake. Pakuti otaya wa polymerase anachita akusowa mphamvu ndi ribonukle-ozidtrifosfato magawo. Ngati aliyense anapanga 3, 5'-phosphodiester ubwenzi ribonukleozidmonofosfatami. Molekyulu RNA kaphatikizidwe kumayambira ena mindandanda DNA (ochirikiza). Dongosololi kumathera pa malo kuchotsa (kuchotsa). malo, zomwe zimafunika apa akutchedwa transcriptional. Mu eukaryotes, pali zambiri jini chimodzi chokha, pamene prokaryotes akhoza adzalandira ndalama zochuluka code. Aliyense transcriptional ali m'dera uninformative. Iwo zili nyukiliotayidi linayamba kugawanika kuti mucheze ndi zinthu transcriptional zolimbana tatchulazi.
Bakiteriya RNA polymerase
Izi tizilombo enzyme ndi udindo kaphatikizidwe wa mRNA, rRNA ndi tRNA. Wapakati polymerase molekyulu ali pafupifupi 5 subunits. Ziwiri kutumikira monga kumangako mamembala enzyme. kagawo kakang'ono wina nawo mwambo wa kaphatikizidwe. Palinso chigawo chimodzi cha enzyme nonspecific kulankhulana ndi DNA. Ndi kagawo kakang'ono otsiriza wakhala akubweretsa RNA polymerase mu mawonekedwe ntchito. Iwo ananena kuti mamolekyulu enzyme sali mu "ufulu" n'kuyamba kusambira mu cytoplasm mabakiteriya. Pamene polymerases RNA ntchito, ndiye amanga zigawo si yeniyeni DNA ndipo akuyembekezera kufikira kulimbikitsa yogwira lidzatsegulidwa. A pang'ono kusokonezeka pa nkhaniyi, ayenera kuti mabakiteriya yabwino kwambiri kuphunzira mapuloteni ndi chikoka chawo pa ribonucleic asidi polymerase. Makamaka yabwino iwo kuyetsa pa kukondoweza kapena chopinga kwa zinthu payekha. Chifukwa mlingo mkulu kubalana akhoza kukhala mofulumira chifukwa ankafuna. Kalanga kuphunzira anthu sangathe kuchitikira pa zikomo ngati mofulumira mayendedwe kuti zosiyanasiyana wathu structural.
RNA polymerase "kukwatulidwa" m'njira zosiyanasiyana?
Izi zimachokera ku kwanzeru nkhani. Chidwi chachikulu linaperekedwa kwa eukaryotes lapansi. Koma pali archaea ndi mavairasi. Choncho mukufuna kulipira pang'ono chidwi ndi mitundu imeneyi ya moyo. The ntchito yofunika ya Archean pali gulu limodzi lokha la polymerases RNA. Koma ndi ofanana kwambiri katundu ndi atatu mayanjano eukaryotes. Asayansi ambiri amanena kuti zimene ife tikhoza kuwona kuchokera Arche kwenikweni kholo zinachokera polymerases apadera. Ndi chidwi ndi kapangidwe ka mavairasi. Monga kale olembedwa, osati onse a zamoyo izi ndi polymerase zawo. Ndipo kumene icho chiri, ndi kagawo kakang'ono umodzi. Akukhulupirira kuti michere ndi tizilombo anachokera ku polymerases DNA, m'malo nyumba zovuta RNA. Ngakhale chifukwa mitundu yosiyanasiyana ya gulu la tizilombo kukhazikitsa osiyana wakumana ndi kuperekedwa limagwirira kwachilengedwenso.
Pomaliza
Kalanga, anthu alibe zomwe vsoy zofunika wofunikila kumvetsa matupi athu ndi. Ndipo kuti iye yekha akanachita! Pafupifupi matenda onse kwenikweni monga maziko majini - imeneyi imagwira makamaka mavairasi amene nthawi zonse amatipatsa mavuto matenda ndi zina zotero. Zovuta kwambiri ndi wosachiritsika matenda - iwonso Kwenikweni, mwachindunji kapena ayi zimadalira matupi a anthu. Pamene taphunzira kumvetsa mwa iwo okha ndipo ntchito zimene ankadziwazo athandize ambiri mavuto ndi matenda amangokhala udzawonongedwa. Tsopano chinthu zapitazi, matenda ambiri m'mbuyomu oopsa monga nthomba, mliri. Kukonzekera kupita mumps, akuphokosera chifuwa. Koma musati asangalale chifukwa takumana ndi chiwerengero kuposa mavuto osiyanasiyana amene muyenera kupeza yankho. Ndipo adzapezeka, chifukwa izo kutero.