4.Universal The genetic codons for amino acids are always the same.(basic reason of microbial infection) With a few exceptions:mitochondrial mRNA, chloroplast. Differences between mitochondrial codons and standard codons Codon Normal sense Mitochondria AUG、AUU、AUA Ile Initiation codon AGA、AGG Arg Terminal codon UGA Terminal codon Trp
4. Universal • The genetic codons for amino acids are always the same. （basic reason of microbial infection） • With a few exceptions ： mitochondrial mRNA, chloroplast . Codon Normal sense Mitochondria AUG、AUU、AUA AGA、AGG UGA Ile Arg Terminal codon Initiation codon Terminal codon Trp Differences between mitochondrial codons and standard codons
S1.2 Amino acid carrier-tRNA/adaptor 3 OH AA arm DHU loop TΨC loop Anticodon loop “Cloverleaf”structure of tRNA
§1.2 Amino acid carrier—tRNA/adaptor Anticodon loop AA arm “Cloverleaf ” structure of tRNA TC loop DHU loop
● tRNA is the bridge between protein and genetic data tRNA 2 Amino Iso-tRNA acid tRNA 3/4/6 relative specificity of transferring
Amino acid tRNA 2 tRNA 3/4/6 ● tRNA is the bridge between protein and genetic data relative specificity of transferring Iso-tRNA
Binding sites in tRNA 3'0 8--R NH2 Attachment site of aa DHU loop (binding rRNA in ribosome) A-C-G mRNA -V-G-C Mathch with codons
O C C H R NH2 O 3' Attachment site of aa Mathch with codons DHU loop (binding rRNA in ribosome) A—C—G mRNA —U—G—C Binding sites in tRNA
摆动性(wobble base pair) Non-Watson-Crick base pairing the 5'base on the anticodon,which binds to the 3' base on the mRNA,was not as spatially confined as the other two bases,and could,thus,have non-standard base pairing
摆动性(wobble base pair) Non-Watson-Crick base pairing the 5' base on the anticodon, which binds to the 3' base on the mRNA, was not as spatially confined as the other two bases, and could, thus, have non-standard base pairing