英汉对照分子生物学导论课件.ppt

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1、Chapter 6 Translation / 翻译,Chapter 6 Translation / 翻译,6.1 The Genetic Code6.2 Mechanism of Translation in Prokaryotes6.3 Translation in Eukaryotes6.4 tRNA Structure and Wobble6.5 Experiments,6.1 遗传密码6.2 原核生物翻译机理6.3 真核生物翻译6.4 tRNA结构与摇摆6.5 实验研究,6.1 The Genetic Code/ 遗传密码,Translation: synthesis of a pr

2、otein using an mRNA as the template.,Transcription,tRNA: the converter,tRNA: the converter,4 bases vs. 20 amino acids,UCAG,Gly,Ala,Ile,Leu,Met,Phe,Trp,Pro,Val,Ser,Thr,Asn,Gln,Cys,Tyr,Asp,Glu,Arg,His,Lys,1 base 1 amino acid,UCAG,Gly,Ala,Ile,Leu,Met,Phe,Trp,Pro,Val,Ser,Thr,Asn,Gln,Cys,Tyr,Asp,Glu,Arg,

3、His,Lys,2 bases 1 amino acid,UUUCUAUG,Gly,Ala,Ile,Leu,Met,Phe,Trp,Pro,Val,Ser,Thr,Asn,Gln,Cys,Tyr,Asp,Glu,Arg,His,Lys,CUCCCACG,AUACAAAG,GUGCGAGG,3 bases 1 amino acid,The genetic code / 遗传密码,6.2 Mechanism of Translation in Prokaryotes原核生物翻译机理,6.2.1 Initiation / 起始6.2.2 Elongation / 延伸6.2.3 Terminatio

4、n / 终止,Composition of prokaryotic ribosome原核生物核糖体的组成,6.2.1 Initiation / 起始,IF-1,Dissociation,IF-3,No reassociation,Separation of 30S and 50S subunits,SD sequence: the translation start signal,16S rRNA,3 end,The 30s initiation complex30S起始复合体,The collection of the 30S subunit, the mRNA, and the initi

5、ator tRNA is called the 30S initiation complex.,The initiator tRNA,The 70S initiation complex,The 70S ribosome,6.2.2 Elongation / 延伸,1) tRNA entering2) Peptidyl transfer3) Translocation4) tRNA leaving,1) tRNA entering / tRNA进入,2) Peptidyl transfer / 肽基转移,3) Translocation / 移位,4) tRNA leaving / tRNA离

6、开,Elongation factors / 延伸因子,Weaver, Molecular Biology, Chapter 18,Elongation factors / 延伸因子,Weaver, Molecular Biology, Chapter 18,6.2.3 Termination / 终止,Translation terminates when ribosome reaches a stop codon, because there is no tRNA being able to bind to the stop codon.,Now showingTranslation: t

7、he three steps,File: biophoto7 Introduction to Genetic Analysis Translation: the three steps of translation (5),6.3 Translation in Eukaryotes真核生物翻译,Composition of eukaryotic ribosome真核生物核糖体的组成,Differences in Translation Initiation翻译起始的不同点,Initiator tRNA / 其始tRNAThe scanning model / 扫描模型,1) Initiator

8、 tRNA / 其始tRNA,CAU,A,Anticodon,fMet-tRNAfMet,Formyl Met A C C5 AC AG C,A* Alkylated adenosine,Anticodon,Met-tRNAMet,Met A C C5 AG CG C,A,G,-引自：Turner, P. C. et al.分子生物学精要速览（影印版），科学出版社，1999，p.249,CAU,Prokaryotic initiator tRNA,Eukaryotic initiator tRNA,Prokaryotic initiator tRNA,70S ribosome,Eukaryot

9、ic initiator tRNA,80S ribosome,CH3,Yeast 80S ribosome,File: Yeast 80S ribosome 1S1I.val,2) The scanning model / 扫描模型,Prokaryotes:SD sequence,The scanning model / 扫描模型,Translation initiated by entering IRES site directly通过直接进入IRES位点启动翻译,IRES: internal ribosome entry sequence,Picornavirus / 小核糖核酸病毒,ww

10、w.uniklinikum-giessen.de/./res_ires.htm,Internal entry,AUG,Translation initiation in eukaryotes (1/4),eIFeukaryotic initiationfactor,Translation initiation in eukaryotes (2/4),Translation initiation in eukaryotes (3/4),Translation initiation in eukaryotes (4/4),6.4 tRNA Structure and WobbletRNA结构与摇摆

11、,6.4.1 Anti-codons / 反密码子,Three-dimensional structure of a tRNA,Aminoacyl-tRNA synthetase: a kind of enzyme that can recognize a tRNAs anticodon and match it with the correct amino acid.,Aminoacyl-tRNA synthetase 氨酰tRNA合成酶,Aminoacyl-tRNA synthetase,Show 3D: synthetase-tRNA complex,File: E coli Thr-t

12、RNA Synthetase Complex 1QF6.val,Anti-codon,Amino acid,6.4.2 Wobble / 摇摆,Wobbling is possible,mRNA,tRNA,DNA,5,5,5,5,Wobbled base pairs,Wobbled base pairs,6.5 Experiments / 实验研究,6.5.1 Deciphering the genetic code 破译遗传密码6.5.2 Direction of translation 翻译的方向,6.5.1 Deciphering the genetic code,Now showingDeciphering the Genetic Code,File: biophoto7 Life Deciphering the genetic code (15),6.5.2 Direction of translation / 翻译的方向,