Dab tsi yog nicked DNA?
Dab tsi yog nicked DNA?

Video: Dab tsi yog nicked DNA?

Video: Dab tsi yog nicked DNA?
Video: Tsis Muaj Dab Tsi Muaj Zog Npaum DNA. 5/23/2022 2024, Kaum ib hlis
Anonim

Lub nick yog qhov tsis sib xws hauv ob txoj hlua khi DNA molecule qhov twg tsis muaj phosphodiester daim ntawv cog lus ntawm cov nucleotides uas nyob ib sab ntawm ib txoj hlua feem ntau los ntawm kev puas tsuaj lossis kev ua enzyme. Nicks tso cai rau qhov xav tau ntau tso tawm ntawm torsion nyob rau hauv lub strand thaum lub sij hawm DNA rov ua dua.

Ib yam li ntawd, koj tuaj yeem nug, dab tsi yog nicked DNA Yuav kho li cas?

Kho ntawm nicks Ligases muaj ntau yam thiab ubiquitous enzymes uas koom nrog 3' hydroxyl thiab 5' phosphate xaus rau tsim ib daim ntawv cog lus phosphodiester, ua rau lawv qhov tseem ceeb hauv nicked DNA kho , thiab thaum kawg genome fidelity. Txhua qhov chaw nick xav tau 1 ATP lossis 1 NAD + rau zog ligase kho.

Dab tsi yog Supercoiled nicked thiab linear DNA? Linearized DNA tshwm sim thaum lub DNA helix yog txiav nyob rau hauv ob qho tib si strands ntawm tib qhov chaw. Linear DNA feem ntau migrate ntawm cov npib lub voj voog thiab lub supercoiled daim ntawv. Txawm li cas los xij, nws kuj tseem tuaj yeem txav mus deb li qub npib voj voog - nws migrate raws li kwv yees los ntawm qhov ntev ntawm lub DNA (raws li piv rau MW cov cim).

Qhov thib ob, DNA nicking yog dab tsi?

A npe enzyme (los yog npe endonuclease) yog ib qho enzyme uas txiav ib txoj hlua ntawm ob txoj hlua khi DNA ntawm ib qho kev paub txog nucleotide ib ntus hu ua qhov chaw txwv. Xws li enzymes hydrolyse (txiav) tsuas yog ib txoj hlua ntawm cov DNA duplex, tsim DNA molecules uas yog "nicked", es tsis cleaved.

Vim li cas tsis txiav DNA plasmid muaj 3 pawg?

Thaum twg tsis txiav plasmid DNA yog cais thiab khiav ntawm agarose gel, koj yog zoo li yuav pom 3 ib band . Qhov no yog vim yog lub voj voog DNA yuav siv sij hawm nyob rau hauv ob peb conformations ntau tshaj yog: supercoiled, so thiab nicked. Yog tias koj txoj kab digest zoo li koj tsis txiav txoj kev ces nyob ntawd yog ib yam dab tsi tsis ncaj ncees lawm!

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