武汉大学生命科学学院：《分子生物学》英文版 CHAPTER 14 Translation

Welcome each of you to My Molecular Biology class @博来字 Wuhan universi

2021/2/21 1 Welcome Each of You to My Molecular Biology Class

Molecular Biology of the Gene 5/E -Watson et al.(2004) Part l: chemistry and genetics Part l: Maintenance of the Genome Part l: Expression of the Genome Part IV: Regulation Part v: Methods

2021/2/21 2 Molecular Biology of the Gene, 5/E --- Watson et al. (2004) Part I: Chemistry and Genetics Part II: Maintenance of the Genome Part III: Expression of the Genome Part IV: Regulation Part V: Methods

2021/2/21 Part III: Expression of the Genome a This part concerned with one of the greatest challenges in understanding the gene how the gene is expressed

2021/2/21 3 Part III: Expression of the Genome ◼ This part concerned with one of the greatest challenges in understanding the gene－ how the gene is expressed

2021/2/21 Part ll: Expression of the Genome Ch 12: Mechanisms of transcription Ch 13: RNA splicing Ch 14: Translation Ch 15: The genetic code translation D NA RNA protein 4

2021/2/21 4 Part III: Expression of the Genome Ch 12: Mechanisms of transcription Ch 13: RNA splicing Ch 14: Translation Ch 15: The genetic code DNA RNA protein translation

一 Chapter 14: Translation

2021/2/21 5 Chapter 14: Translation

2021/2/21 Translation extremely costs In rapid growing bacterial cells protein synthesis consumes a80% of the cell's energy 50% of the cell's cell's dry weight Why?

2021/2/21 6 Translation extremely costs In rapid growing bacterial cells, protein synthesis consumes ◼ 80% of the cell’s energy ◼ 50% of the cell’s cell’s dry weight Why?

2021/2/21 The main challenge of translation -The genetic information in mRNA cannot be recognized b amino acids a The genetic code has to be recognized by an adaptor molecular(translator, and this adaptor has to accurately recruit the corresponding amino acid

2021/2/21 7 The main challenge of translation ◼ The genetic information in mRNA cannot be recognized by amino acids. ◼ The genetic code has to be recognized by an adaptor molecular (translator), and this adaptor has to accurately recruit the corresponding amino acid

2021/2/21 Translation machinery 1. mRNAs(N5%of total cellular RNA) 2. trNas(~15%) 3. aminoacyl-tRNA synthetases (氨酰tRNA合成酶) 4. ribosomes(N100 proteins and 3-4 TRNAs-~80%)

2021/2/21 8 Translation machinery 1. mRNAs (~5% of total cellular RNA) 2. tRNAs (~15%) 3. aminoacyl-tRNA synthetases (氨酰tRNA合成酶) 4. ribosomes (~100 proteins and 3-4 rRNAs--~80%)

Outline 2021/2/21 Topics 1-4: Four components of translation machinery T1-mRNA: T2-tRNA: T3-Attachment of amino acids to tRNa (aminoacyl tRNa synthetases)i T4-The ribosome Topic 5-6: Translation process. T5-initiation; T6-elongation; T7 termination Topic 8: Translation-dependent regulation of mRNA and protein stability

2021/2/21 9 Outline Topics 1-4: Four components of translation machinery. T1-mRNA; T2-tRNA; T3-Attachment of amino acids to tRNA (aminoacyl￾tRNA synthetases); T4-The ribosome Topic 5-6: Translation process. T5-initiation; T6-elongation; T7- termination. Topic 8: Translation-dependent regulation of mRNA and protein stability

2021/2/21 Topic 1: mRNA a Only a portion of each mRNA can be translated a The protein-coding region of the mrna consists of an ordered series of 3 -nt-long units called codons that specify the order of amino acids 10

2021/2/21 10 Topic 1: mRNA ◼ Only a portion of each mRNA can be translated. ◼ The protein-coding region of the mRNA consists of an ordered series of 3-nt-long units called codons that specify the order of amino acids