Qhov Tseem Ceeb Qhov txawv - Prokaryotic vs Eukaryotic RNA Polymerase
RNA polymerase yog cov enzyme uas yog lub luag haujlwm rau cov txheej txheem ntawm kev hloov pauv uas tshwm sim hauv txhua yam kab mob. RNA polymerase yog lub siab molecular hnyav enzyme. Lub npe ntawm RNA polymerase yog DNA qhia RNA polymerase. Thaum lub sij hawm luam ntawv, RNA polymerase qhib ob-stranded DNA kom ib DNA strand yuav siv tau raws li ib tug template rau cov txheej txheem ntawm synthesizing ib mRNA molecule. Tsim cov RNA (mRNA, rRNA, thiab tRNA) molecules yog ib kauj ruam tseem ceeb hauv cov protein synthesis (kev txhais lus). Cov txheej txheem kev hloov pauv thiab cov kev hloov pauv hloov pauv hloov pauv yog coj RNA polymerase enzyme los pib qhov kev hloov pauv hauv lub cell nyob. RNA polymerase txuas mus rau thaj tsam txhawb nqa ntawm cov noob (DNA) thiab pib RNA polymerase-catalyzed transcription. Prokaryotic thiab eukaryotic transcription sib txawv vim qhov sib txawv ntawm RNA polymerase enzyme. Qhov sib txawv tseem ceeb ntawm Prokaryotic thiab Eukaryotic RNA Polymerase yog qhov kev hloov pauv ntawm prokaryotic yog ua los ntawm ib hom subunit ntawm RNA polymerase. Ntawm qhov tsis sib xws, eukaryotic transcription yog catalyzed los ntawm peb hom RNA polymerases hu ua RNA polymerase I (transcribe rRNA), RNA polymerase II (transcribe mRNA) thiab RNA polymerase III (transcribe tRNA).
Prokaryotic RNA Polymerase yog dab tsi?
Lub prokaryotic RNA polymerase yog ib qho enzyme hnyav ntau. RNA polymerase ntawm E coli tau kawm ntau heev. Qhov no yog ib qho enzyme complex uas muaj qhov hnyav molecular ntawm 450 KDa. Lub holoenzyme muaj ob lub ntsiab lus tseem ceeb. Lawv yog cov tseem ceeb enzyme thiab transcription yam tseem ceeb. Lub ntsiab enzyme tivthaiv yog muaj tsib subunits xws li β', β, αI, αII thiab ω. Cov ntsiab lus hloov pauv yog sigma yam (initiation), nusA (elongation).
Tawm ntawm cov xwm txheej no, β' muaj txoj haujlwm ntawm DNA khi. Thiab β yam muaj qhov chaw catalytic uas ua rau RNA polymerization. Lub zog ntawm yam α thiab ω tseem tsis tau pom. Qee tus hais tias alpha yam (α) yog lub luag haujlwm rau kev pib saws thiab kev cuam tshuam nrog cov proteins tswj. Lub luag haujlwm tseem ceeb ntawm kev ua sigma yog kev txhawb nqa kev lees paub. Thaum tus txhawb nqa hauv DNA tau lees paub los ntawm qhov zoo tshaj plaws sigma, cov khoom siv coenzyme ntawm RNA polymerase khi nrog thaj tsam txhawb nqa thiab pib RNA polymerization. Thaum transcription pib lub sigma yam tawm los ntawm DNA. Lub elongation ntawm RNA molecule yog ua los ntawm β subunit. Hauv kev txiav cov saw hlau, "rho yam" tso tawm RNA molecule uas twb muaj lawm.
Daim duab 01: Tus Prokaryotic RNA Polymerase
Cov lus sau tseg xaus ntawm qhov chaw teev tseg los ntawm DNA qauv. Qhov zoo tshaj nusA yog koom nrog hauv kev ua haujlwm ntawm elongation nrog rau kev txiav cov saw hlau. Cov tshuaj tua kab mob rifampicin tuaj yeem khi nrog cov beta subunit ntawm cov kab mob RNA polymerase. Li no, nws tiv thaiv cov enzyme los ntawm kev pib cov kab mob RNA polymerization. Lwm cov tshuaj tua kab mob hu ua streptolydigin inhibits cov txheej txheem elongation ntawm cov kab mob RNA polymerization. Cov prokaryotes mRNA yog polycistronic, txhais tau tias nws muaj codons ntawm ntau tshaj ib cistron (ntau tshaj ib lub noob).
YEukaryotic RNA Polymerase yog dab tsi?
Cov eukaryotic RNA polymerases yog peb hom sib txawv. Lawv sau ntau hom genes. Thiab tseem ua haujlwm nyob rau hauv cov xwm txheej sib txawv. Qhov pib thiab txiav cov yam tseem ceeb (sigma thiab rho yam) yog txawv kiag li ntawm prokaryotic RNA polymerase counterparts. Peb qhov sib txawv RNA polymerases muaj npe xws li, RNA polymerase I (transcripts rRNA), RNA polymerase II (transcribes mRNA) thiab RNA polymerase III (transcribes tRNA). RNA polymerase I nyob rau hauv lub nucleolus thiab enzyme xav tau Mg2+ rau nws txoj haujlwm. RNA polymerase II yog nyob rau hauv nucleoplasm thiab xav tau ATP rau nws cov haujlwm. RNA polymerase III kuj tseem nyob hauv nucleoplasm.
Cov neeg txhawb nqa rau cov RNA polymerases txawv. RNA polymerase Kuv paub txog cov neeg txhawb nqa hauv nruab nrab ntawm -45 txog +25 thaj tsam hauv DNA. RNA polymerase II lees paub cov neeg txhawb nqa hauv nruab nrab ntawm -25 txog -100 thaj tsam hauv DNA xws li (TATA lub thawv, CAAT lub thawv, thiab GC lub thawv). RNA polymerase III paub txog cov kev txhawb nqa sab hauv qis.
Daim duab 02: Eukaryotic RNA Polymerase
Cov eukaryotic RNA polymerases yog cov complex loj uas ua los ntawm ntau subunits proteins ntawm 500 kDa lossis ntau dua. Lawv muaj cov txheej txheem sib txawv rau cov txheej txheem pib thiab cov txheej txheem elongation xws li, TFIIA, TFIIB, TFIID, TFIIE, TFIIF, TFIIH, TFIIJ. RNA polymerization terminates los ntawm RNA polymerase kuv tom qab pom Sal box. RNA polymerization termination los ntawm RNA polymerase II tshwm sim tom qab pom cov cim hauv qab lub npe hu ua polyA tail. Thiab RNA polymerase III paub txog deoxyadenylate residues ntawm tus qauv thiab txiav tawm cov ntawv sau. Eukaryotic mRNA yog ib txwm monocistronic.
Dab tsi zoo sib xws ntawm Prokaryotic thiab Eukaryotic RNA Polymerase?
- Ob leeg koom nrog RNA synthesizing.
- Ob leeg siv DNA ua tus qauv.
- ob leeg yog cov protein ntau.
- Ob leeg muaj qhov sib txawv uas pib sau.
- Ob leeg muaj cov ntsiab lus hloov pauv uas tswj cov kauj ruam (pib thiab elongation) ntawm RNA polymerization.
Qhov txawv ntawm Prokaryotic thiab Eukaryotic RNA Polymerase yog dab tsi?
Prokaryotic vs Eukaryotic RNA Polymerase |
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| Cov prokaryotic RNA polymerase yog ib qho ntawm ntau lub subunits hom enzyme uas yog lub luag haujlwm rau prokaryotic transcription. | Cov Eukaryotic RNA polymerases yog ntau hom enzymes uas ua rau eukaryotic transcription. |
| Molecular Nyhav | |
| Tus prokaryotic RNA polymerase molecular hnyav yog kwv yees li 400 KDa. | Lub Eukaryotic RNA polymerases molecular hnyav yog ntau tshaj 500kD. |
| Cov ntsiab lus sau npe | |
| Cov prokaryotic RNA polymerase muaj cov khoom hloov pauv xws li sigma factor thiab nusA. | Cov Eukaryotic RNA polymerases muaj ntau yam kev hloov pauv rau kev pib thiab elongation xws li; TFIIA, TFIIB, TFIID, TFIIE, TFIIF, TFIIH, TFIIJ |
| Termination Factor | |
| Cov prokaryotic RNA polymerase muaj "rho yam" rau kev txiav. | Cov Eukaryotic RNA polymerases muaj qhov sib txawv ntawm kev txiav tawm xws li sal box, poly A tail, deoxyadenylate residues. |
| Promoters | |
| Tus prokaryotic RNA polymerase lees paub tus txhawb nqa hauv -10 txog -35 cheeb tsam hauv DNA hu ua TATA lub thawv. | The Eukaryotic RNA polymerases lees paub cov neeg txhawb nqa sib txawv1. |
| Nature of mRNA | |
| Prokaryotic RNA polymerase tsim polycistronic mRNA. | Lub Eukaryotic RNA polymerase II tsim cov monocistronic mRNA. |
1 RNA polymerase Kuv lees paub cov neeg txhawb nqa hauv nruab nrab ntawm -45 txog +25 thaj tsam hauv DNA. RNA polymerase II lees paub cov neeg txhawb nqa hauv nruab nrab ntawm -25 txog -100 thaj chaw hauv DNA xws li (TATA lub thawv, CAAT lub thawv, thiab GC lub thawv). RNA polymerase III paub txog cov kev txhawb nqa sab hauv qis.
Summary – Prokaryotic vs Eukaryotic RNA Polymerase
RNA polymerase yog enzyme lub luag haujlwm rau RNA polymerization hu ua transcription hauv cell nyob. RNA polymerase tseem muaj npe hu ua DNA-directed RNA polymerase raws li nws siv DNA ua tus qauv. Hauv kev sau ntawv RNA polymerase ib txwm qhib ob txoj hlua DNA kom ib qho DNA strand tuaj yeem siv los ua tus qauv rau cov txheej txheem ntawm kev sib txuas RNA molecule. RNA polymerase tuaj yeem ua rau mRNA, rRNA, thiab tRNA. Cov txheej txheem kev hloov pauv thiab kev hloov pauv hloov kho qhov nyuaj yog coj RNA polymerase hauv cov txheej txheem hloov pauv. Cov ntawv sau muaj peb kauj ruam; pib, elongation, thiab xaus. Qhov no tuaj yeem qhia tau tias qhov txawv ntawm Prokaryotic thiab Eukaryotic RNA Polymerase.
Download PDF Version ntawm Prokaryotic vs Eukaryotic RNA Polymerase
Koj tuaj yeem rub tawm PDF version ntawm kab lus no thiab siv nws rau offline lub hom phiaj raws li daim ntawv ceeb toom. Thov download PDF version ntawm no Qhov txawv Ntawm Prokaryotic thiab Eukaryotic RNA Polymerase
