Protein synthesis ntawm ribosomes, uas yog, kev txhais lus ntawm nucleotide sib lawv liag ntawm mRNA rau hauv cov amino acid ib ntus ntawm cov protein, yog cov txheej txheem cyclic. Nyob rau hauv txhua puag ncig ntawm elongation, ob tRNA molecules ua ke nrog cov mRNA txav los ntawm ribosome nyob rau hauv ib tug multistep txheej txheem hu ua translocation.
Kev hloov pauv tshwm sim nyob qhov twg hauv cov protein synthesis?
Thaum lub sijhawm sib txuas cov protein, mRNA thiab tRNAs tau txav mus dhau ntawm ribosome los ntawm cov txheej txheem hloov pauv hloov pauv. Kev txav mus los ntawm tRNAs los ntawm qhov chaw A (aminoacyl) mus rau P (peptidyl) site mus rau E (tawm) qhov chaw yog ua ke nrog kev txav ntawm lawv cov codons cuam tshuam hauv mRNA.
Dab tsi ua kom yooj yim hloov pauv ntawm ribosome ntawm mRNA?
tRNA–mRNA translocation yog txhawb los ntawm elongation factor G (EF-G) ntawm tus nqi ntawm GTP hydrolysis. … EF-G pab txhawb kev tsim cov kev hloov ntawm lub ribosome thiab uncouples rov qab motions ntawm lub ribosomal subunits, tsim ib tug qhib conformation nyob rau hauv uas cov tRNAs tuaj yeem txav tau sai.
Puas ribosome txav thaum lub sijhawm hloov chaw?
Ribosome dynamics yog ib qho tseem ceeb tsis yog tsuas yog hauv kev hloov pauv, tab sis kuj tseem nyob rau hauv cov xwm txheej rov qab, xws li kev hloov pauv thiab hla, thiab kho kom haum rau cov tshuaj tua kab mob. Thaum lub sij hawm elongation theem ntawm kev txhais lus ribosome txav raws mRNA thaum synthesising nascent polypeptide.
Qhov twg cuam tshuam rau kev hloov pauv ntawm ribosome raws mRNA?
Kev hloov chaw yog catalyzed los ntawm an elongation factor (EF-G hauv Escherichia coli) thiab koom nrog kev txav mus los ntawm cov molecules loj (mRNA thiab ob tRNAs) nyob rau qhov ntev (∼ 50 Å) nyob rau hauv lub ribosome.
