Qhov sib txawv tseem ceeb ntawm sigma factor thiab rho yam yog tias sigma yam yog ib qho protein uas xav tau rau kev pib ntawm cov kab mob hauv cov kab mob thaum rho factor yog cov protein uas xav tau rau kev txiav tawm ntawm cov kab mob hauv cov kab mob.
Sigma factor thiab rho factor yog ob yam tseem ceeb rau cov kab mob transcription. Bacterial transcription yog ib txoj kev uas ib daim ntawm cov kab mob DNA tau theej rau hauv ib tug tshiab strand ntawm mRNA (messenger RNA). Cov txheej txheem no yog catalyzed los ntawm ib qho enzyme hu ua RNA polymerase. Cov kab mob loj heev vam khom rau kev sau ntawv thiab kev txhais lus kom teb rau lawv ib puag ncig kom zoo. Cov kab mob RNA polymerase muaj cov tub ntxhais thiab cov qauv holoenzyme. Cov tub ntxhais muaj cov subunits β, β ′, α thiab 2ω thaum lub holoenzyme muaj cov sigma yam. Tsis tas li ntawd, ib qho tseem ceeb rau RNA polymerase hu ua rho yam tseem ceeb heev rau cov kab mob transcription.
Sigma Factor yog dab tsi?
Sigma yam lossis qhov tshwj xeeb yog cov protein uas xav tau rau kev pib ntawm kev hloov pauv hauv cov kab mob. Nws yog ib qho kab mob transcription pib qhov tseem ceeb. Qhov no ua rau muaj kev sib txuas ntawm RNA polymerase enzyme rau thaj tsam tshwj xeeb ntawm DNA hu ua thaj tsam txhawb nqa thaum lub sijhawm sau ntawv. Sigma feem ntau yog homologous rau archaeal transcription factor B thiab rau eukaryotic transcription factor TF11B. Tsis tas li ntawd, qhov tshwj xeeb sigma ntawm cov noob tau muab sib txawv nyob ntawm cov noob thiab ib puag ncig cov cim. Cov neeg txhawb nqa raug xaiv los ntawm RNA polymerase nyob ntawm qhov sib txawv ntawm qhov cuam tshuam nrog nws.
Daim duab 01: Sigma Factor
Qhov tseem ceeb ntawm sigma kuj tuaj yeem pom hauv chloroplast ntawm cov nroj tsuag ua ib feem ntawm plastid-encoded polymerase (PEP). Sigma yam thiab RNA polymerase tag nrho yog hu ua RNA polymerase holoenzyme. Qhov hnyav molecular ntawm sigma yam yog nyob ib ncig ntawm 70 kDa. Tom qab pib ntawm kev hloov pauv, qhov cuam tshuam sigma dissociates los ntawm txoj kev. Tom qab ntawd RNA polymerase txuas ntxiv elongation kom txog thaum cov ntaub ntawv txiav tawm.
Rho Factor yog dab tsi?
Rho yam yog ib qho prokaryotic protein koom nrog hauv kev txiav cov ntawv sau. Rho yam feem ntau khi rau qhov chaw sau npe ncua sij hawm ncua. Qhov chaw no yog thaj chaw nthuav tawm ntawm ib leeg-stranded RNA nyob ze ntawm qhov qhib kev nyeem ntawv ntawm cytosine nplua nuj guanine tsis zoo ib ntus. Nws yog ib qho tseem ceeb transcription protein nyob rau hauv prokaryotes. Nyob rau hauv Escherichia coli, rho yam yog kwv yees li 274.6 kDa hexamer ntawm tib subunits. Txhua lub subunit muaj RNA binding domain thiab ATP hydrolysis domain. Ntxiv mus, qhov ua haujlwm ntawm rho yam yog qhov ua haujlwm helicase.
Daim duab 02: Rho Factor
Rho yam khoom khi rau RNA molecule thiab tom qab ntawd siv nws cov haujlwm ATPase los muab lub zog los hloov pauv RNA molecules. Rho qhov tseem ceeb nqa tawm kev hloov pauv mus txog thaum nws mus txog RNA-DNA helical cheeb tsam, qhov uas nws unwinds hybrid (RNA-DNA) duplex qauv. Cov txheej txheem no nres RNA polymerase ntawm qhov chaw txiav tawm txiav tawm cov txheej txheem hloov pauv.
Dab tsi yog qhov zoo sib xws ntawm Sigma Factor thiab Rho Factor?
- Sigma factor thiab rho factor yog ob yam tseem ceeb rau cov kab mob transcription.
- Ob leeg tsuas muaj nyob hauv prokaryotes xwb.
- Lawv yog cov proteins uas ua los ntawm cov amino acids.
- Ob leeg yog nucleic acids khi cov proteins.
- Prokaryotes hnyav hnyav rau cov yam no los tsim mRNA uas tuaj yeem ua cov protein tshwj xeeb thiab pab lawv teb rau lawv ib puag ncig tshwj xeeb.
Qhov txawv ntawm Sigma Factor thiab Rho Factor yog dab tsi?
Sigma yam yog ib qho protein uas xav tau rau kev pib ntawm kev hloov pauv hauv cov kab mob, thaum rho yam yog cov protein uas xav tau rau kev txiav tawm ntawm cov kab mob. Yog li, qhov no yog qhov sib txawv tseem ceeb ntawm sigma factor thiab rho factor. Tsis tas li ntawd, qhov zoo tshaj plaws sigma yog DNA binding protein, thaum lub rho yam yog RNA binding protein.
Cov hauv qab no nthuav qhia txog qhov sib txawv ntawm Sigma qhov sib txawv thiab RHRO qhov kev sib piv rau sab nrog sab sib piv.
Summary – Sigma Factor vs Rho Factor
Kev txhais lus yog txheej txheem uas cov ntaub ntawv hauv DNA tau theej rau hauv ib lub molecule tshiab hu ua mRNA (tus tub txib RNA). Qhov m-RNA no thaum kawg koom nrog hauv kev tsim cov protein tshwj xeeb. Sigma factor thiab rho factor yog ob yam tseem ceeb rau cov kab mob transcription. Lawv yog cov protein. Sigma yam koom nrog hauv kev pib ntawm kev hloov pauv hauv cov kab mob. Rho yam tseem ceeb yog lub luag haujlwm rau kev txiav tawm ntawm cov kab mob hauv cov kab mob. Yog li, qhov no yog cov ntsiab lus ntawm qhov sib txawv ntawm sigma factor thiab rho factor.
