Dab tsi yog DNA polymerase kuaj xyuas kev hloov pauv?
Dab tsi yog DNA polymerase kuaj xyuas kev hloov pauv?

Video: Dab tsi yog DNA polymerase kuaj xyuas kev hloov pauv?

Video: Dab tsi yog DNA polymerase kuaj xyuas kev hloov pauv?
Video: Koj paub dab tsi txog cov tshuaj txhaj tiv thaiv kab mob COVID-19? 2024, Lub peb hlis ntuj
Anonim

Thaum DNA synthesis, thaum ib qho tsis raug nucleotide tau muab tso rau hauv tus ntxhais strand ntawm DNA , DNA polymerase rov qab los ntawm ib khub nucleotide, excises lub mismatched nucleotide thiab kho yuam kev. Yog li ntawd, lub DNA polymerase kuaj xyuas kev hloov pauv ntawm lub sijhawm DNA replication.

Ua kom pom qhov no, DNA polymerase tiv thaiv kev hloov pauv li cas?

Cov haujlwm proofreading ntawm DNA polymerase yog lub luag haujlwm rau kev tiv thaiv ntawm kev hloov pauv uas tshwm sim thaum rov ua dua . Ib zaug ib DNA polymerase kuaj pom qhov tsis raug nucleotide hauv paus hauv cov saw loj loj, nws nres rov ua dua thiab tshem tawm cov nucleotide tsis raug los ntawm kev ua haujlwm exonuclease thiab tiv thaiv kev hloov pauv.

Tom qab ntawd, lo lus nug yog, DNA polymerase ua li cas thiaj kuaj tau qhov yuam kev? DNA polymerase proofreading: proofreading los ntawm DNA polymerase kho yuam kev thaum rov ua dua . Kev Kho Tsis Zoo: Hauv kev kho tsis sib haum, qhov tsis raug-ntxiv lub hauv paus yog kuaj pom tom qab rov ua dua . Cov mismatch-kho cov proteins ntes lub hauv paus no thiab tshem tawm nws los ntawm qhov tshiab-synthesized strand los ntawm nuclease nkaus.

Hauv qhov no, DNA polymerase pov thawj li cas?

DNA polymerases yog cov enzymes tsim DNA hauv hlwb. Thaum DNA replication (copy), feem ntau DNA polymerases tuaj yeem ua tau "xyuas lawv cov haujlwm" nrog rau txhua lub hauv paus uas lawv ntxiv. Cov txheej txheem no yog hu ua kev nyeem ntawv . Polymerase siv 3' mus rau 5' exonuclease kev ua kom tshem tawm qhov tsis raug T los ntawm 3' kawg ntawm txoj hlua tshiab.

Dab tsi yog kev sib raug zoo ntawm DNA polymerases thiab kev hloov hauv DNA?

DNA polymerase tuaj yeem tiv thaiv a DNA mutation los ntawm qhov tshwm sim lossis nws tuaj yeem rov qab mus kho qhov teeb meem tsim. Gene qhia yog qhov tshwm sim ntawm noob rau hauv cov yam ntxwv tshwj xeeb.

Pom zoo: