Qhov sib txawv tseem ceeb ntawm SF1 thiab SF2 yog lawv lub peev xwm los daws cov nucleic acids. Thaum SF1 tsuas yog unwinds DNA, SF2 unwinds DNA thiab RNA.
Helicase yog ib qho ntawm cov enzymes tseem ceeb uas koom nrog hauv DNA replication txheej txheem nrog rau cov txheej txheem kho DNA. Lub luag haujlwm tseem ceeb ntawm helicase yog koom nrog hauv cov txheej txheem unwinding txhawm rau pab txhawb kev sib cais ntawm ob-stranded DNA molecules. Kev ua haujlwm ntawm enzyme yog qhov tseem ceeb thaum lub sijhawm pib ntawm DNA replication. Helicases tau muab faib ua Super Family 1 thiab Super Family 2 feem ntau raws li lawv cov qauv sib txawv. Hauv txhua tsev neeg Super, muaj ntau hom helicases.
SF1 yog dab tsi?
Super Family 1 helicase yog ib hom helicase uas muaj cov qauv hexameric nrog rau cov ntsiab lus tseem ceeb hauv lub cev, uas qhia txog kev ua haujlwm helicase. SF1 helicase yog ib qho ntawm cov chav kawm loj tshaj plaws ntawm helicase thiab tuaj yeem raug cais ntxiv raws li SF1A helicases thiab SF1B helicases. Proteins xws li PcrA, Rep thiab UvrD, yog nyob rau hauv chav kawm ntawm SF1A helicases. Hauv kev sib piv, cov proteins xws li RecA thiab Dda yog nyob rau hauv chav kawm ntawm SF1B helicases. Cov haujlwm ntawm SF1 helicases sib txawv. Qee qhov haujlwm tseem ceeb ntawm SF1 helicases suav nrog DNA replication, DNA recombination, Okazaki fragment processing, telomere tsim, thiab nucleotide excision kho DNA puas. Hauv qee hom kab mob, SF1 hom helicases kuj koom nrog hauv kev pab hloov cov noob kab rov tav ntawm kev sib txuas. Tsis tas li ntawd, nyob rau hauv cov kab mob, SF1 helicases pab nyob rau hauv kis kab mob.
Daim duab 01: Helicase Action
Muaj ntau yam sib txawv nrog rau cov qauv ntawm SF1 helicases. Lawv muaj tsawg kawg yog 7 qhov kev khaws cia ntawm txhua yam sib txawv ntawm SF1 helicases (Q, I, Ia, II, III, IV, V, thiab VI). Cov qauv ntawm SF1 helicase yog siv lead ua, qhov twg cov motifs yog pawg ua ke. Muaj tus yam ntxwv ATP khi hnab tshos nruab nrab ntawm cov motifs thiab DNA binding site. Cov tsis-conserved domains yog muab faib los tuav lub structural kev ncaj ncees ntawm lub helicase molecule. Cov npe no tuaj yeem sib txawv ntawm SF1A helicases thiab SF1B helicases.
SF2 yog dab tsi?
Super family 2 helicase yog ib pawg neeg sib txawv ntawm helicase superfamilies. Muaj ntau hom SF2 helicases xws li RecQ-zoo li helicases, RecG - zoo li helicases, Rad3 / XPD thiab NS3 helicases. Qee qhov txwv enzymes, xws li hom I txwv enzymes, kuj poob rau hauv pawg no. Kev ua haujlwm dav dav ntawm SF2 helicases yog qhov kev sib tw ntawm ob txoj hlua DNA. Txawm li cas los xij, qee hom SF2 helicases tsis muaj peev xwm ua tiav raws li helicase enzymes. SF2 helicases tau dav siv hauv RNA ua ib yam nkaus. DEAD-box tsev neeg ntawm SF2 helicases koom nrog hauv RNA ua, suav nrog kev sau ntawv, kev sib txuas, kev txhais lus thiab RNA-protein complex sib dhos.
Daim duab 02: Helicase
Cov qauv ntawm SF2 helicase kuj muaj cov qauv kev txuag. Txawm li cas los xij, qee qhov chaw txawv me ntsis ntawm SF1 helicase. Lawv kuj muaj ATP binding domain sib nrug ntawm DNA binding domain.
Dab tsi yog qhov Zoo sib xws ntawm SF1 thiab SF2?
- SF1 thiab SF2 qhia txog kev ua haujlwm helicase.
- Ntxiv mus, ob qho tib si koom nrog DNA replication thiab recombination.
- SF1 thiab SF2 yog tsim los ntawm kev txuag motifs.
- Ob leeg muaj ATP binding domain thiab DNA binding domain.
- Cov ntaub ntawv no yog cov protein ntau ntau.
- Ntxiv mus, yog tias kev hloov pauv tshwm sim hauv ob hom, nws yuav ua rau muaj kev cuam tshuam tsis zoo.
- Ob leeg SF1 thiab SF2 yog qhov tseem ceeb los xyuas kom meej lub voj voog ntawm tes.
- SF1 thiab SF2 muaj nyob hauv prokaryotes thiab hauv eukaryotes.
Qhov txawv ntawm SF1 thiab SF2 yog dab tsi?
SF1 thiab SF2 yog ob tsev neeg super ntawm helicase. Lawv qhia txog ntau haiv neeg. Qhov sib txawv tseem ceeb ntawm SF1 thiab SF2 yog tias SF1 feem ntau koom nrog hauv kev hloov pauv ntawm DNA, thaum SF2 kuj koom nrog hauv RNA ua thaum lub sijhawm sau ntawv thiab txhais lus. Thaum muab piv cov motifs sib txawv ntawm cov protein, SF1 thiab SF2 feem ntau txawv raws li motif III thiab motif IV. Txawm hais tias lawv muaj cov qauv zoo sib xws, SF1 helicases tsim cov qauv toroidal hexameric thaum SF2 tsis tsim cov qauv txheej txheem.
Lwm qhov txawv ntawm SF1 thiab SF2 yog tias SF1 helicases nyiam adenine nucleotides ntau dua, thaum SF2 helicases nyiam tag nrho tsib nucleotides rau lub hom phiaj rau unwinding. Thaum muab piv cov kev taw qhia unwinding, SF1 helicases tsuas yog translocate nyob rau hauv 5 'mus rau 3' kev taw qhia, thaum SF2 helicases muaj peev xwm mus translocate nrog rau cov nucleic acids nyob rau hauv ob qho tib si qhia.
Cov ntawv qhia hauv qab no nthuav tawm qhov sib txawv ntawm SF1 thiab SF2 hauv daim ntawv tabular rau ib sab ntawm kev sib piv.
Summary – SF1 vs SF2
Helicases yog ib pab pawg tseem ceeb thiab muaj ntau hom enzymes uas koom nrog DNA replication. Txawm li cas los xij, vim nws muaj ntau haiv neeg, enzymes tau categorized rau hauv superfamilies. SF1 thiab SF2 yog ob tsev neeg loj tshaj plaws ntawm helicases. Thaum SF1 feem ntau cuam tshuam nrog kev ua haujlwm ntsig txog DNA, SF2 cuam tshuam nrog DNA thiab RNA ua. Yog li, qhov no yog qhov sib txawv tseem ceeb ntawm SF1 thiab SF2. Tsis tas li ntawd, SF1 thiab SF2 kuj sib txawv hauv lawv qhov kev teeb tsa raws li SF2 tsis tsim cov qauv hexameric. Kev hloov pauv hauv SF1 thiab SF2 helicases yuav ua rau kev txhim kho mob qog noj ntshav tom qab dysregulation ntawm lub voj voog ntawm tes thiab lwm yam tseem ceeb xws li kho DNA.
