Qhov Tseem Ceeb Qhov txawv - DNA Ligase vs DNA Polymerase
DNA ligase thiab DNA polymerase yog cov enzymes tseem ceeb koom nrog hauv DNA replication thiab DNA kho mechanisms ntawm kab mob. DNA ligase yog lub luag hauj lwm rau kev koom nrog DNA fragments los ntawm catalyzing tsim phosphodiester bonds ntawm nucleotides. DNA polymerase yog lub luag haujlwm rau kev sib txuas ntawm DNA los ntawm nws lub tsev blocks (nucleotides) siv cov qauv DNA. Qhov no yog qhov txawv ntawm DNA ligase thiab DNA polymerase.
DNA Ligase yog dab tsi?
DNA ligase yog ib qho enzyme uas catalyzes tsim cov phosphodiester daim ntawv cog lus ntawm 3' - OH thiab 5'- PO 4 pawg nucleotides thiab pab txhawb kev koom nrog DNA tawg. Nws tseem hu ua molecular stitcher. Qhov peev xwm no ua rau lub qhov khoob lossis cov nicks ntawm DNA thiab koom nrog Okazaki fragments tsim thaum DNA replication. DNA ligases muaj txiaj ntsig zoo hauv kev siv thev naus laus zis DNA thev naus laus zis rau kev tsim cov recombinant DNA molecules. DNA ligase koom nrog DNA ntawm kev txaus siab nrog vector DNA. Yog li ntawd, nws yog ib qho tseem ceeb enzyme rau kab mob.
DNA ligase enzyme nyob ntawm ib cofactor thiab Mg2+ ions rau nws txoj haujlwm. Muaj ob cofactors uas pab hauv DNA ligases. NAD+ ua tus cofactor rau cov kab mob DNA ligases thaum ATP feem ntau ua raws li tus kab mob cofactor thiab eukaryotic DNA ligases. Eukaryotic DNA ligase ua tiav ntawm peb kauj ruam tseem ceeb.
Kauj Ruam 01. DNA ligase tawm tsam ATP molecule thiab tso tawm pyrophosphate (ob pawg phosphate) thiab AMP, thiab tsim ligase-adenylate nruab nrab los ntawm kev khi covalently nrog cov txiaj ntsig AMP.
Kauj Ruam 02: Tsim cov enzyme AMP intermediate hloov AMP mus rau 5 'phosphate ntawm nick thiab tsim DNA - adenylate (5'-phosphate oxygen ntawm DNA strand tawm tsam phosphorus ntawm ligase-adenylate nruab nrab).
Kauj Ruam 03: DNA ligase catalyzes nres ntawm 3′-OH ntawm nick ntawm DNA-adenylate los koom nrog polynucleotides thiab tso tawm AMP.
DNA ligases feem ntau yog cais los ntawm T4 bacteriophage thiab siv dav hauv cov tshuab DNA recombinant.
Daim duab 01: DNA ligase hauv kev kho nick
YDNA Polymerase yog dab tsi?
DNA polymerase yog ib qho enzyme uas muaj nyob rau hauv tag nrho cov kab mob koom nrog hauv DNA synthesis thiab genome replication. Cov ntaub ntawv caj ces dhau los ntawm niam txiv mus rau cov xeeb ntxwv nrog kev pab ntawm DNA polymerases. Nws catalyzes cov synthesis ntawm DNA tshiab ntxiv rau cov DNA uas twb muaj lawm. DNA polymerase ntxiv nucleotides (lub tsev blocks ntawm nucleic acids) mus rau 3 'OH pab pawg neeg ntawm primer sequence thiab txuas ntxiv cov strand tsim mus rau 5' kev taw qhia. Feem ntau ntawm DNA polymerases muaj 5' rau 3' polymerase kev ua haujlwm thiab 3' mus rau 5' exonuclease kev ua rau kev ua pov thawj.
Prokaryotic DNA polymerases tau piav qhia hauv tsib pawg loj. Eukaryotes muaj tsawg kawg yog 16 qhov sib txawv DNA polymerases. Tag nrho cov DNA polymerases no tau muab faib ua xya tsev neeg xws li A, B, C, D, X, Y, thiab RT (Rov qab transcriptase).
Daim duab 02: DNA polymerase tsav DNA replication
Dab tsi yog qhov txawv ntawm DNA Ligase thiab DNA Polymerase?
DNA Ligase vs DNA Polymerase |
|
| DNA ligase yog ib qho enzyme uas catalyzes tsim cov phosphodiester bonds ntawm nucleotides thiab txuas DNA fragments ua ke. | DNA polymerase yog ib qho enzyme uas catalyzes cov synthesis ntawm DNA siv nucleotides. |
| Role hauv DNA Replication | |
| DNA ligase yog ib qho enzyme ntxiv hauv DNA replication uas koom nrog Okazaki fragments. | DNA polymerase yog lub ntsiab enzyme hauv DNA replication. |
| Yuav tsum | |
| Nws nyob ntawm Mg2+ ions thiab ATP/NAD+ cofactors | Nws nyob ntawm tus qauv, nucleotides, primers thiab Mg2+. |
| Functions | |
| DNA ligase yog ib qho tseem ceeb rau DNA recombination, DNA kho thiab DNA replication. | DNA polymerase tseem ceeb rau DNA replication, DNA kho thiab DNA recombination technology. |
Summary – DNA Ligase vs DNA Polymerase
DNA ligase yog ib qho tseem ceeb enzyme uas xav tau los koom nrog DNA tawg los ntawm phosphodiester bonds. DNA polymerase yog lub ntsiab enzyme tseem ceeb rau DNA synthesis tshiab. Qhov sib txawv tseem ceeb ntawm DNA ligase thiab DNA polymerase yog lawv txoj haujlwm. Txawm li cas los xij, ob qho enzymes yog qhov tseem ceeb rau kev kho DNA, DNA replication thiab recombinant DNA technology.
