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 (aminoacyltRNA 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