BIOCHEMISTRYANDMOLECULARBIOLOGYChapter 32Biosynthesis of ProteinDepartment of Biochemistry and Molecular Biology,Medicine School
Department of Biochemistry and Molecular Biology, Medicine School BIOCHEMISTRY AND MOLECULAR BIOLOGY Chapter 32 Biosynthesis of Protein
ABIOCHEMISTRYANDMOLECULARBIOLOGYOutline*Overview*Substance for protein synthesis*Biosynthesis of Protein*Post-Translational Modification ofPolypeptideChainsDepartment of Biochemistry and Molecular Biology,Medicine School
Department of Biochemistry and Molecular Biology, Medicine School BIOCHEMISTRY AND MOLECULAR BIOLOGY Outline *Overview *Substance for protein synthesis *Biosynthesis of Protein *Post- Translational Modification of Polypeptide Chains
BIOCHEMISTRYANDMOLECULARBIOLOGY1.overviewGeneexpressionDNATemplatestrandTranscriptionmRNAACCodonTranslationProteinMetProAlaLeuArgfaminoacid chain)AlanineMethionineProlineLeucineArginineeSchool
Department of Biochemistry and Molecular Biology, Medicine School BIOCHEMISTRY AND MOLECULAR BIOLOGY 1. overview
XBIOCHEMISTRYANDMOLECULARBIOLOGY2.Substancefor protein synthesis> mRNA----Template for translation>Ribosome--- Place for protein synthesis>tRNA---Transfer amino acid> The other substanceDepartment of Biochemistry and Molecular Biology,Medicine School
Department of Biochemistry and Molecular Biology, Medicine School BIOCHEMISTRY AND MOLECULAR BIOLOGY 2. Substance for protein synthesis ➢ mRNA-Template for translation ➢Ribosome- Place for protein synthesis ➢tRNA-Transfer amino acid ➢ The other substance
BIOCHEMISTRYANDMOLECULARBIOLOGYmRNA----Template for protein synthesisComponent of genetic codon:>Three of nucleotide in mRNA form a genetic codon,one codon represent one amino acid.>Four kinds of nucleotides comprise 64 codons, 61represent amino acid, 3 of them (UAA、UAG、UGA)are termination codonDepartment of Biochemistry and Molecular Biology,Medicine School
Department of Biochemistry and Molecular Biology, Medicine School BIOCHEMISTRY AND MOLECULAR BIOLOGY Component of genetic codon： ➢Three of nucleotide in mRNA form a genetic codon， one codon represent one amino acid. ➢Four kinds of nucleotides comprise 64 codons，61 represent amino acid，3 of them（UAA、UAG、UGA） are termination codon. mRNA-Template for protein synthesis
Gene expressionDNATemplatestrandTranscriptionCmRNA1CodonTranslationProteinMetProLeuAlaArgTaminoacidchain)MethionineProlineLeucineAlanineArginine
Department of Biochemistry and Molecular Biology, Medicine School BIOCHEMISTRY AND MOLECULAR BIOLOGY
Second letterGUCAUUUUUAUUGUPhenyl-UCUTyrosineCysteineUUCUACCUGCUCCalanineUSerineUCAAUGAUUAUAAStopcodonStop.codonLeucineUCGUAGUUGGUGGStopcodonTryptophanUCAUCGUCUUCCUHistidineCACCCCCCGCCUCProlineLeucineArginineCGACCACUAACAAGlutamineCGGCUGCCGCAGGUAAUAGUAUUACUSerineAsparagineAGCAUCAACIsoleucineCACC-ThreonineAUAACAMethionineAAAAAGALysineArginineACGinitiationAUGAAGAGGGcodonUGAUGUUGCUAsparticGGUGACCGCCGGCGUCacidGValineAlanineGlycineGUAGCAGGAAGAAGlutamicGUGGCGGGGGAGGacid
Department of Biochemistry and Molecular Biology, Medicine School BIOCHEMISTRY AND MOLECULAR BIOLOGY
CAU启HHMetHHGAUStart CodonGGAOGGCUGCCCCUCCOU剪mmnC35
Department of Biochemistry and Molecular Biology, Medicine School BIOCHEMISTRY AND MOLECULAR BIOLOGY
AUGlyPheGluHHHHSerHHAAStopCodonAAN(also UAG and UGA)UCCCCCOLCUU35
Department of Biochemistry and Molecular Biology, Medicine School BIOCHEMISTRY AND MOLECULAR BIOLOGY
mRNA----Template for protein synthesisCharacteristics of codon:>Commaless:The genetic code is nonoverlapping and commaless- that is,the code is read from a fixed starting point as a continuoussequence of bases, taken three at a time.>Degeneracy(Redundancy):(1) Besides Trp （W) and Met （M) ， The other aminoacids have more than one triplet genetic codon.(2) It usually change on the third of nucleotide in thenucleotide -codonDepartment of Biochemistry and Molecular Biology,MedicineSchool
Department of Biochemistry and Molecular Biology, Medicine School BIOCHEMISTRY AND MOLECULAR BIOLOGY Characteristics of codon： ➢Commaless: The genetic code is nonoverlapping and commaless- that is, the code is read from a fixed starting point as a continuous sequence of bases, taken three at a time. ➢Degeneracy(Redundancy): (1) Besides Trp（W) and Met（M），The other amino acids have more than one triplet genetic codon. (2) It usually change on the third of nucleotide in the nucleotide codon mRNA-Template for protein synthesis