Qhov sib txawv tseem ceeb ntawm Shine Dalgarno thiab Kozak sequence yog qhov Shine Dalgarno sequence yog ib qho chaw ribosomal binding site nyob rau hauv cov kab mob thiab archaeal messenger RNA, thaum Kozak sequence yog ib tug protein txhais lus pib qhov chaw nyob rau hauv feem ntau eukaryotic messenger RNAs.
Shine Dalgarno thiab Kozak ib ntus yog ob qhov kev pom zoo uas tseem ceeb heev rau kev pib txhais lus. Hauv molecular biology, kev txhais lus yog cov txheej txheem uas ribosomes nyob rau hauv cytoplasm synthesize proteins tom qab cov txheej txheem ntawm transcription. Hauv kev txhais lus, ib qho mRNA (tus tub txib RNA) tau txiav txim siab hauv ribosome los tsim cov amino acid tshwj xeeb hauv cov nucleus. Feem ntau, ib qho ribosome induces tus txheej txheem decoding los ntawm kev ua kom yooj yim ntawm kev sib txuas ntawm tRNA anticodon sequences rau mRNA codons. Kev txhais lus pib nyob rau hauv peb theem: pib, elongation thiab termination.
Shine Dalgarno Sequence yog dab tsi?
Shine Dalgarno ib ntus yog qhov sib txuas ntawm ribosomal hauv cov kab mob thiab archaeal messenger RNA. Nws yog feem ntau nyob ib ncig ntawm 8 lub hauv paus ntawm qhov pib codon AUG. Qhov RNA ntu no pab nrhiav cov ribosomes rau tus tub txib RNA los ntawm kev ua kom cov ribosome nrog mRNA pib codon. Yog li, nws pib tsim cov protein synthesis. Ib zaug tom qab nrhiav neeg ua haujlwm, tRNA tuaj yeem ntxiv cov amino acids raws li tau hais los ntawm mRNA codons. Cov kab ke tshwj xeeb no muaj nyob hauv cov kab mob tab sis tsis tshua muaj nyob hauv archaea. Tsis tas li ntawd, nws tseem muaj nyob hauv chloroplast thiab mitochondrial transcripts. Shine Dalgarno ib ntus yog thawj zaug los ntawm Australian kws tshawb fawb John Shine thiab Lynn Dalgarno. Lub rau lub hauv paus kev pom zoo ib ntus yog AGGAGG. Piv txwv li, hauv Escherichia coli cov kab ke yog AGGAGGU.
Daim duab 01: Ci Dalgarno Sequence
Kev xaiv ntawm qhov chaw pib (AUG) nyob ntawm kev sib cuam tshuam ntawm 30S subunit ntawm ribosome thiab mRNA template. Pyrimidine nplua nuj cheeb tsam ntawm 16srRNA tivthaiv ntawm 30S subunit khi rau thaj tsam purine-nplua nuj hu ua Shine Dalgarno sib lawv liag ntawm AUG pib codon hauv mRNA. Tsis tas li ntawd, thaum lub sij hawm tsim ntawm kev pib ua haujlwm, cov nucleotide sib txuas ua ke ua ke los ua ib qho qauv RNA ob npaug. Qhov no ua kom yooj yim rau kev khi ntawm mRNA rau ib qho ribosome hauv txoj kev uas pib codon muab tso rau ntawm P site ntawm ribosome.
Kozak Sequence yog dab tsi?
Kozak ib ntus yog qhov chaw pib txhais lus protein nyob hauv feem ntau eukaryotic mRNA. Cov kab ke no tseem hu ua Kozak kev pom zoo ib ntus. Kozak ib ntus yog qhov zoo tshaj plaws rau kev pib txhais lus hauv eukaryotes. Cov kab ke no yog ib qho tseem ceeb ntawm kev tswj hwm cov protein. Nws kuj tseem ceeb heev rau kev noj qab haus huv ntawm cellular tag nrho. Nws pab kom raug cov protein txhais lus los ntawm cov lus caj ces los ntawm kev sib kho ribosome los ua ke thiab pib txhais lus.
Daim duab 02: Kozak Sequence
Cov kab lus no tau muab npe tom qab tus kws tshawb fawb uas pom nws, Marilyn Kozak. Nws tshawb pom nws los ntawm kev txheeb xyuas cov ntsiab lus ntawm DNA genomic sequences. Kozak sequence yog 5' (gcc) gccRccAUGG-3'. Cov tsiaj ntawv loj qhia cov hauv paus khaws cia, thaum cov tsiaj ntawv me qhia cov hauv paus sib txawv. R qhia txog purine (adenine lossis guanine) uas ib txwm nyob hauv qhov chaw no.
Dab tsi zoo sib xws ntawm Shine Dalgarno thiab Kozak Sequence?
- Shine Dalgarno thiab Kozak ib ntus yog ob qhov kev pom zoo ib ntus uas tseem ceeb heev hauv kev pib txhais lus.
- ob leeg yog RNA sequences.
- Lub subunit me ntawm lub ribosome khi rau ob qho tib si sequences.
- Ob qhov kev sib txuas kho kom haum rau kev sib dhos ribosome thiab pib txhais lus.
- Lawv yog qhov tseem ceeb ntawm kev tswj hwm cov protein thiab kev noj qab haus huv ntawm tes.
Qhov txawv ntawm Shine Dalgarno thiab Kozak Sequence yog dab tsi?
Shine Dalgarno ib ntus yog qhov chaw sib txuas ribosomal pom nyob rau hauv cov kab mob thiab archaeal messenger RNA, thaum Kozak sequence yog qhov chaw pib txhais lus protein pom nyob rau hauv feem ntau eukaryotic messenger RNA. Yog li, qhov no yog qhov sib txawv tseem ceeb ntawm Shine Dalgarno thiab Kozak ib ntus. Tsis tas li ntawd, Shine Dalgarno sequence yog 5'AGGAGGU3' thaum, Kozak sequence yog 5' (gcc) gccRccAUGG-3'.
Cov infographic hauv qab no teev qhov sib txawv ntawm Shine Dalgarno thiab Kozak ib ntus hauv daim ntawv teev npe rau ib sab ntawm kev sib piv.
Summary – Shine Dalgarno vs Kozak Sequence
Shine Dalgarno thiab Kozak sequences yog ob qhov kev pom zoo RNA ib ntus uas tseem ceeb heev rau kev sib dhos ribosome thiab pib txhais lus. Shine Dalgarno sequence yog ib qhov chaw ribosomal binding site nyob rau hauv cov kab mob thiab archaeal tub txib RNA, thaum Kozak ib theem zuj zus yog ib tug protein txhais lus pib qhov chaw nyob rau hauv feem ntau eukaryotic tub txib RNA. Yog li, qhov no qhia txog qhov sib txawv ntawm Shine Dalgarno thiab Kozak ib ntus.
