Eukaryotic and prokaryotic mrNAs Have major differences-I procaryotic mRNA coding noncoding sequence sequence ⊙PP protein a proteinβ proteinγ eucaryotic mRNA coding noncoding sequence sequence 团 5′ AAAAA150-250 3 5 (A) protein Figure 6-22 part 1 of 2. Molecular Biology of the Cell, 4th Edition
Eukaryotic and Prokaryotic mRNAs Have Major Differences - I
Eukaryotic and prokaryotic MrNAs Have maior differences -ll 5′ end of 7-methylguanosine primary transcript HO OH c!H2⊙CH2 OF 5′-to-5′ (B) triphosphate bridg CH H OH Figure 6-22 part 2 of 2. Molecular Biology of the Cell, 4th Edition
Eukaryotic and Prokaryotic mRNAs Have Major Differences - II
Ribosome核糖体 原核生物核糖体 真核生物核糖体 70sM27×10° 80sM4.2x10 A supramolecular complex of rRNAS and proteins, the BOS site of protein synthesis Have two subunit In eukaryotes binding in M.18×105 M28×10° RER: in prokaryotes SSTRNA 5S TRNA 28S RNA 28S TRNA 5.88 tRNA binding in mRNA 6种蛋白质 19种蛋白质 M.0.9×10° M.1.4×10 16S rRNA 18SrRNA 21种蛋白质 3种蛋白质
Ribosome核糖体 • A supramolecular complex of rRNAs and proteins, the site of protein synthesis • Have two subunit • In eukaryotes, binding in RER; in prokaryotes, binding in mRNA
rrna processing in prokaryotes Seven different operons for rRNA rrn dispersed bought out the genome Each operons transcript a 30S( 6000bp) primary transcript Each primary transcript contains one copy of 5s, 16S and 23S rRNA, together with some tRNA sequence Rnase lll is involved in rRNa processing
一、rRNA processing in prokaryotes • Seven different operons for rRNA rrn dispersed thought out the genome • Each operons transcript a 30S(~6000bp) primary transcript • Each primary transcript contains one copy of 5S,16S and 23S rRNA, together with some tRNA sequence • Rnase III is involved in rRNA processing
Rnase in e coli E.cli中含有的小分子核酸酶 酶 基因 底物 功能 RNasep A tRNA5′端 内切 Rnase rnpB RnaseBN tRNA3′端 外切 Rnase rnd tRNA3′端 外切 Rnase tRNA3′CCA外切 Rnaselll rRNA和mRNA 内切 Naser rRNA和mRNA外切 Rnase rne 5s rrNA 内切 Rnase I n 大部分RNA 内切 RnaseⅡ b RNA 外切 多核苷酸磷酸化酶pp RNA 外切 Rnaseh rn h RNA-DNA杂合链内切
Rnase in E.coli • E.coli中含有的小分子核酸酶 酶 基因 底物 功能 RNaseP rnpA tRNA 5′端 内切 RnaseO rnpB RnaseBN ? tRNA 3′端 外切 RnaseD rnd tRNA 3′端 外切 RnaseT ? tRNA 3′CCA 外切 RnaseⅢ rnc rRNA和mRNA 内切 RnaseR ? rRNA和mRNA 外切 RnaseE rne 5S rRNA 内切 RnaseⅠ rna 大部分RNA 内切 RnaseⅡ rnb RNA 外切 多核苷酸磷酸化酶 pnp RNA 外切 RnaseH rnh RNA-DNA杂合链 内切