Qhov Tseem Ceeb Qhov txawv - Taq Polymerase vs DNA Polymerase
DNA polymerase yog ib qho enzyme uas tsim DNA tshiab los ntawm nws lub tsev blocks (nucleotides). Hauv prokaryotes thiab eukaryotes, muaj ntau hom DNA polymerases pom. DNA duplication yog ua tau vim muaj cov enzymes tshwj xeeb, thiab cov ntaub ntawv caj ces raug xa mus rau cov xeeb ntxwv los ntawm kev ua ntawm DNA polymerases. Taq polymerase yog ib hom tshwj xeeb ntawm DNA polymerase uas yog thermostable thiab dav siv hauv PCR. Taq polymerase muaj nyob rau hauv cov kab mob thermophilic thiab purified nyob rau hauv vitro DNA replication. Qhov sib txawv tseem ceeb ntawm Taq polymerase thiab DNA polymerase yog tias Taq polymerase tuaj yeem tiv taus qhov kub thiab txias yam tsis muaj denaturing thaum lwm cov DNA polymerases denature ntawm qhov kub siab (ntawm cov protein degrading kub).
Taq Polymerase yog dab tsi?
Taq polymerase (Taq DNA polymerase) yog ib qho enzyme siv los ua ke DNA hauv vitro los ntawm PCR txheej txheem. Nws yog tsim los ntawm cov kab mob thermophilic hu ua Thermus aquaticus uas nyob hauv cov dej kub thiab cov cua sov. Taq polymerase yog ib qho thermostable enzyme uas tsis degrade ntawm qhov kub thiab txias. Taq polymerase tau huv si thawj zaug thiab luam tawm hauv Chien li al. nyob rau xyoo 1976. PCR txheej txheem yog ua nrog kev pab ntawm Taq polymerase vim nws lub peev xwm los tiv taus qhov kub thiab txias hloov pauv thaum lub sijhawm PCR. Taq polymerase catalyzes DNA synthesis thaum muaj primers, nucleotides thiab ib leeg-stranded template DNA. Lub enzyme muaj ib qho polypeptide nrog ib qho hnyav molecular ntawm kwv yees li 94 kDa. Taq polymerase qhia tau hais tias nws qhov kev ua tau zoo tshaj plaws ntawm 80 ° C thiab ntawm 7 - 8 pH ntau yam nrog rau cov Magnesium ions. Nws muaj ob qho tib si polymerase thiab exonuclease kev ua haujlwm. Lub enzyme yog tsim los ntawm ib leeg polypeptide saw thiab cov noob rau Taq polymerase muaj G thiab C cov ntsiab lus siab (67.9%).
Thermostable Taq polymerase tso cai rau kev ua PCR ntawm qhov kub thiab txias uas ua rau muaj qhov tshwj xeeb ntawm primers thiab txo qis ntawm kev tsim cov khoom PCR tsis xav tau (primer dimers). Taq polymerase kuj tseem tshem tawm qhov xav tau ntxiv cov enzymes tshiab rau PCR cov tshuaj tiv thaiv tom qab txhua qhov kev cuam tshuam PCR vim nws muaj peev xwm tiv taus qhov kub thiab txias. Kev tshawb pom ntawm Taq polymerase tau ua rau PCR ua haujlwm hauv ib lub raj kaw hauv lub tshuab yooj yim. Vim cov khoom no ntawm Taq polymerase, PCR dhau los ua cov txheej txheem kev sim ua haujlwm nrov hauv ntau cov tshuaj lom neeg biology txog DNA tsom xam.
Taq polymerase yog siv dav hauv cov txheej txheem lom neeg molecular, thiab yuav tsum muaj qhov loj-scale Taq polymerase ntau lawm. Yog li ntawd, siv cov thev naus laus zis DNA rov ua dua thiab cov noob cloning, cov noob uas encoded Taq DNA polymerase tau raug cloned thiab qhia hauv Escherichia coli. Qhov no tau ua kom yooj yim heev rau kev tsim cov khoom siv recombinant Taq polymerase thiab txo tus nqi ntawm cov enzyme no rau kev siv txaus.
Daim duab 1: Taq Polymerase
YDNA Polymerase yog dab tsi?
DNA polymerase yog ib qho enzyme uas catalyzes DNA synthesis ntawm nucleotides. Nws yog qhov tseeb tshaj plaws enzyme lub luag haujlwm rau duplicating genomes thiab dhau cov ntaub ntawv caj ces rau cov xeeb ntxwv. Thaum lub sij hawm faib cell, DNA polymerase duplicates tag nrho nws cov DNA thiab dhau ib daim ntawv rau txhua tus ntxhais cell. Xyoo 1955, Arthur Kornberg tau tshawb pom DNA polymerase hauv E Coli. Kev ua haujlwm ntawm DNA polymerase nyob ntawm ntau qhov yuav tsum tau ua; template DNA, Mg+2 ions, tag nrho plaub hom deoxynucleotides (dATP, dTTP, dCTP thiab d GTP), thiab luv luv ntawm RNA (primer). Synthesis ntawm DNA yog ua nyob rau hauv cov kev taw qhia ntawm 5'to 3' los ntawm DNA polymerase.
DNA polymerases tuaj yeem muab faib ua xya tsev neeg: A, B, C, D, X, Y, thiab RT (Reverse transcriptase). Retroviruses encode rau RT; Ib qho txawv txav DNA polymerase uas xav tau RNA qauv rau DNA synthesis. Muaj tsib hom DNA polymerases pom nyob rau hauv prokaryotes rau ntau lub luag haujlwm hauv DNA replication. DNA polymerase 3 yog lub luag haujlwm rau lub polymerization ntawm cov strand tshiab ntawm DNA. DNA polymerase 1 yog lub luag haujlwm kho thiab kho DNA. DNA polymerases 2, 4 thiab 5 yog lub luag haujlwm kho thiab ua pov thawj DNA. Hauv eukaryotes, muaj 15 hom DNA polymerases. Lawv suav nrog tsib tsev neeg loj.
Daim duab 2: DNA Polymerase
DNA polymerases yog siv rau hauv noob caj noob ces, PCR, DNA sequencing, SNP nrhiav, molecular diagnostics, thiab lwm yam
Qhov txawv ntawm Taq Polymerase thiab DNA Polymerase yog dab tsi?
Taq Polymerase vs DNA Polymerase |
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| Taq DNA polymerase yog ib qho enzyme uas tsim DNA. Nws yog ib qho thermostable enzyme pom nyob rau hauv thermophiles | DNA polymerase yog ib qho enzyme uas pab txhawb DNA replication thiab pom nyob rau hauv ob qho tib si prokaryotic thiab eukaryotic kab mob. |
| Kev poob qis ntawm qhov kub siab | |
| Taq polymerase ua haujlwm ntawm qhov kub thiab txias. | DNA polymerases degrade ntawm protein denaturing kub. |
| Qhov no yog siv dav hauv PCR | Taq polymerase hloov DNA polymerase los ntawm coli Ameslikas siv hauv PCR. |
Summary – Taq Polymerase vs DNA Polymerase
DNA polymerases yog cov enzymes uas tsim cov DNA los ntawm deoxynucleotides (lub tsev thaiv ntawm DNA) thaum lub template thiab primers muaj. DNA polymerases yuav tsum tau muab faib ua cov hlwb DNA thiab dhau mus rau hauv cov menyuam ntxhais zoo tib yam thaum lub sijhawm faib ntawm tes. DNA polymerases ntxiv nucleotides tshiab rau 3' kawg ntawm cov primer thiab elongate DNA tshiab strand synthesis rau hauv 5' mus rau 3' kev taw qhia. Taq DNA polymerase yog ib qho ntawm DNA polymerase enzyme uas muaj txiaj ntsig zoo hauv polymerase chain reaction (PCR) txoj kev ntawm DNA amplification. E. coli DNA polymerase 1 tau siv ua ntej rau PCR, tab sis kev lag luam Taq polymerase supplanted nws vim nws qhov tshwj xeeb ntawm primer binding ntawm qhov kub thiab txias thiab zus tau tej cov yield ntau dua ntawm cov khoom uas xav tau nrog tsawg dua cov khoom lag luam amplification. Qhov no yog qhov txawv ntawm Taq Polymerase thiab DNA Polymerase.
