Qhov sib txawv tseem ceeb ntawm aminoacyl tRNA thiab peptidyl tRNA yog qhov aminoacyl tRNA yog tRNA molecule khi rau A site ntawm ribosome thaum peptidyl tRNA yog tRNA molecule khi rau P site ntawm ribosome.
Transfer RNA (tRNA) yog RNA molecule uas pab txiav txim siab tus tub txib RNA (mRNA) sib lawv liag rau hauv cov protein. Hauv kev sib xyaw ua ke ntawm cov protein, tRNA molecule ua lub hauv paus ua khub nrog nws qhov sib ntxiv ntawm mRNA (tus tub txib RNA). Qhov no ua kom ntseeg tau tias cov amino acid uas tsim nyog tau muab tso rau hauv cov saw hlau polypeptide (protein molecule). Yog li, tRNA yog ib qho tseem ceeb rau kev txhais cov kauj ruam ntawm cov protein synthesis. Aminoacyl tRNA thiab peptidyl tRNA yog ob hom tRNA molecules uas koom nrog cov kauj ruam txhais ntawm cov protein synthesis.
Aminoacyl tRNA yog dab tsi?
Aminoacyl tRNA yog tRNA molecule uas dais ib qho amino acid ntawm qhov kawg. Nws feem ntau khi rau qhov chaw nyob ib sab ntawm ribosome. Cov aminoacyl tRNA, nrog rau tshwj xeeb elongation yam, xa cov amino acid tshwj xeeb rau ribosome rau kev koom ua ke rau hauv cov saw hlau polypeptide thaum txhais lus. Txhua amino acid muaj nws tus kheej tshwj xeeb aminoacyl tRNA synthetase enzyme. Cov enzyme no yog siv los ntawm cov amino acids rau chemically khi rau qhov tshwj xeeb tRNA. Kev khi ntawm tRNA nrog nws cov cognate amino acid yog qhov tseem ceeb. Qhov no ua kom ntseeg tau tias tsuas yog cov amino acid tshwj xeeb uas phim cov anticodon ntawm tRNA yog siv thaum lub sij hawm tsim cov protein. Txhawm rau tiv thaiv kev txhais lus yuam kev, aminoacyl tRNA synthetase enzyme muaj peev xwm ua pov thawj. Cov amino acids uas yog misacylated nrog rau qhov zoo tRNA molecule feem ntau undergo hydrolysis. Qhov no yog ua los ntawm deacylation mechanism ntawm aminoacyl tRNA synthetase enzyme. Tsis tas li ntawd, lub mischarged tRNA yuav tsum tau hydrolyzed thiaj li yuav tiv thaiv cov protein synthesis tsis raug.
Daim duab 01: Aminoacyl tRNA
Ntxiv rau qhov muaj nuj nqi hauv kev tsim cov protein, aminoacyl tRNA kuj tseem tuaj yeem ua haujlwm ua tus pub ntawm cov amino acids tsim nyog rau kev hloov kho lipids thiab biosynthesis ntawm cov tshuaj tua kab mob. Ntxiv mus, nws tseem nkag siab tias pawg noob tuaj yeem siv aminoacyl tRNA los tswj cov synthesis ntawm encoded polypeptides.
YPeptidyl tRNA yog dab tsi?
Peptidyl tRNA yog tRNA molecule uas khi rau P site ntawm ribosome. Tom qab kev pib ua haujlwm tau tsim kom zoo, kev txhais lus pib los ntawm elongation ntawm polypeptide. Lub ribosome muaj peb qhov chaw rau tRNA khi: P (peptidyl), A (aminoacyl) thiab E (muaj nyob).
Daim duab 02: Peptidyl tRNA
Tus pib methionyl tRNA ib txwm khi rau P site. Tom ntej no aminoacyl tRNA khi rau A qhov chaw nrog kev pab los ntawm ib qho elongation yam (EF-Tu hauv prokaryotes thiab eEf-1α hauv eukaryotes) thiab GTP. Tom qab khi, GDP (hydrolyzed GTP) molecule raug tso tawm. Tom qab ntawd, daim ntawv cog lus peptide yog tsim los ntawm methionyl tRNA ntawm P site thiab qhov thib ob aminoacyl tRNA ntawm qhov chaw A. Cov tshuaj tiv thaiv no yog catalyzed los ntawm peptidyl transferase enzyme. Cov tshuaj tiv thaiv no hloov methionine mus rau aminoacyl tRNA ntawm qhov chaw A, yog li tsim peptidyl tRNA. Ntxiv mus, thaum lub sij hawm translocation theem, peptidyl tRNA txav mus rau P site ntawm ribosome nrog kev pab los ntawm elongation yam (EFG hauv prokaryotes thiab eEf-2 hauv eukaryotes) thiab GTP hydrolysis. Tsis tas li ntawd, lub uncharged tRNA thawj zaug tsiv mus rau E site ntawm lub ribosome ces tawm ntawm E site thaum kawg ntawm tus txheej txheem.
Dab tsi yog qhov zoo sib xws ntawm Aminoacyl tRNA thiab Peptidyl tRNA?
- Aminoacyl tRNA thiab peptidyl tRNA yog ob hom tRNA molecules uas koom nrog kev txhais lus.
- Ob leeg yog tRNA molecules ua los ntawm ribonucleotide hauv paus: adenine, cytosine, guanine, thiab uracil.
- Amino acids cuam tshuam nrog ob lub molecules.
- Lawv ua lub luag haujlwm tseem ceeb hauv kev tsim cov protein.
- Ob leeg koom nrog cov kauj ruam ntawm kev txhais lus.
Qhov txawv ntawm Aminoacyl tRNA thiab Peptidyl tRNA yog dab tsi?
Aminoacyl tRNA yog tRNA molecule uas khi rau A qhov chaw ntawm ribosome, thaum peptidyl tRNA yog tRNA molecule uas khi rau P site ntawm ribosome. Yog li, qhov no yog qhov sib txawv tseem ceeb ntawm aminoacyl tRNA thiab peptidyl tRNA. Tsis tas li ntawd, aminoacyl tRNA dais ib qho amino acid ntawm lub terminus thaum peptidyl tRNA dais cov peptide saw ntawm lub terminus.
Cov hauv qab no infographic teev qhov sib txawv ntawm aminoacyl tRNA thiab peptidyl tRNA nyob rau hauv daim ntawv tabular rau ib sab sib piv.
Summary – Aminoacyl tRNA vs Peptidyl tRNA
tRNA yog ib qho molecule uas pab txiav txim siab ib theem mRNA rau hauv cov protein. Aminoacyl tRNA thiab peptidyl tRNA yog ob hom tRNA molecules uas koom nrog cov txheej txheem txhais lus. Aminoacyl tRNA raug khi rau A qhov chaw ntawm ribosome thaum lub sijhawm kev txhais lus, thaum peptidyl tRNA raug khi rau P site ntawm ribosome thaum lub sijhawm txhais lus. Yog li, qhov no qhia txog qhov sib txawv ntawm aminoacyl tRNA thiab peptidyl tRNA.
