同济大学：《细胞的生物化学》课程电子教案（PPT课件）Genetic information transfer——Protein Biosynthesis Translation（翻译）

Objectives After completion of this section,you should be able to 1.List molecules (Aminoacyl tRNA synthetase)involved in protein Synthesis 2.Describe the process of protein synthesis 3.Post-translational processing and destination of newly synthesized protein. 4.Inhibitors of protein synthesis

Objectives After completion of this section, you should be able to : 1. List molecules (Aminoacyl tRNA synthetase) involved in protein Synthesis 2. Describe the process of protein synthesis 3. Post-translational processing and destination of newly synthesized protein. 4. Inhibitors of protein synthesis

Protein synthesis:using mRNAas the template,translate the nucleotide sequence of mRNAinto the amino acid sequence of protein according to the genetic codon. AB四AGa g aoA月a月圆 Codon1 Codon2 Codon3 Codon4 Codon5 TRANSLATION peptide bond Polypeptide COOH Amino Amino Amino Acid 1 Acid 3 Acid 4

Protein synthesis: using mRNA as the template, translate the nucleotide sequence of mRNA into the amino acid sequence of protein according to the genetic codon

03 LTCCAATOGCATTTCCTTAAGCEATA Replication Transcription 5了TTT1111 UCC UACUUGUUCC G AU U Translation ARG

Translation Transcription Replication

Outline of the section 1.System of protein biosynthesis 2.Process of protein translation 3.Post-translational modification 4.Inhibitors of protein synthesis

Outline of the section 1. System of protein biosynthesis 2. Process of protein translation 3. Post-translational modification 4. Inhibitors of protein synthesis

Section 1 Protein Biosynthesis System

Protein Biosynthesis System Section 1

Protein synthetic System Direct template-mRNA ●tRNA ●Ribosomes 20 amino acids (AA) ●Enzyme and protein factors:F、eF、EF、RF ·ATP、GTP、Mg2+ Characteristics:complicated,accurate, dynamic,quick,energy consumed (90%)

● 20 amino acids (AA) ● Enzyme and protein factors: IF、eIF、EF、RF ● ATP、GTP、Mg2+ Protein synthetic System ⚫ Direct template— mRNA ⚫ tRNA ⚫ Ribosomes Characteristics：complicated, accurate, dynamic,quick, energy consumed（90%）

S 1.1 Genetic codon carrier-mRNA ●base→amino acid conversion:Genetic code a three-nucleotide codon in a nucleic acid (mRNA) sequence specifies a single amino acid,initiatior codon or terminator codon.This kind of three-nucleotide codon is called genetic codon or triplet codon. Initiator codon:AUG Terminator codon:UAA、UAG、UGA

§1.1 Genetic codon carrier-mRNA ● base amino acid conversion：Genetic code a three-nucleotide codon in a nucleic acid (mRNA) sequence specifies a single amino acid, initiatior codon or terminator codon. This kind of three-nucleotide codon is called genetic codon or triplet codon. Initiator codon: AUG Terminator codon: UAA、UAG、UGA

Standard Genetic codon U A G UUU UCU UAU UGU Phe Cys U UUC UCC Tyr Ser UAC UGC UUA UCA UAA Stop UGA Stop UUG Leu 内 UCG UAG Stop UGG Trp CUU CCU- CAU His CGU U cUc CCC CAC CGc First Leu Pro Arg CUA CCA CAA Third position GIn CGA A CUG CCG CAG CGG G position (5'end) AUU U (3'end) ACU AAU AGU Asn A AUC ACC AAC Ser Thr AGC AUA ACA AAA Lys AGA Arg AUG ACG AAG AGG G GUU GCU GAUT Asp GGU ☑ G GUC Val GCC Ala GAC GGC GAA Gly GUA GCA Glu GGA GUG GCG GAG GGG G Amino acid names Ala alanine GIn glutamine Leu leucine Ser serine Arg=arginine Glu glutamate Lys =lysine Thr threonine Asn =asparagine Gly glycine Met methionine Trp tryptophan Asp aspartate His histidine Phe phenylalanine Tyr Tyrosine Cys =cysteine Tle =Isolevcine Pro proline Val valine

Standard Genetic codon

Salient features Sense codon:code for amino acid -61. Nonsense codon:code for no amino acid-terminator codon-UAA,UAG,UGA Initiator codon as initiation signal for translation AUG,GUG(prokaryote)

Sense codon：code for amino acid — 61. Nonsense codon：code for no amino acid— terminator codon—UAA，UAG，UGA Initiator codon ：as initiation signal for translation — AUG, GUG(prokaryote) . Salient features

A complete sequence of mRNA,from the initiation codon (AUG)to the termination codon,is termed as the open reading frame_(ORF),which codes for the primary structure of polypeptide. ORF 5 AUG UAA 3 UTR UTR

A complete sequence of mRNA, from the initiation codon (AUG) to the termination codon, is termed as the open reading frame (ORF), which codes for the primary structure of polypeptide. 5 ' A U G U A A 3 ' ORF UTR UTR