BIOL308 Lecture Notes - Transferase, Transfer Rna, Prokaryote
16 Jul 2014
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Document Summary
Elongation; similar in prokaryotes and eukaryotes met is on the p site. Elongation of a protein chain has three steps: Amino-acyl-trna, couples with tu-ts (in prokaryotes) or eef1-eef1b (in eukaryotes) and gtp into ternary complex, binds to a site on ribosome and pairs with codon on mrna. Peptide bond forms between previous aa and new aa: peptidyl transferase reaction. Previous aa is transferred/bound to the aa carried by amino-acyl-trna which now becomes peptidyl-trna; it is still at the a site. Ribosome moves 3" to move another codon into the a site. Translocation is catalyzed by ef g(pro) or eef2 (eu), using gtp energy. empty trna is now at the e site. New amino-acyl-trna (ternary complex) binds to a site. Another rna having catalytic activity: trna makes direct contact with both 16s and 23s rrnas in ribosome rrna are ighly conserved (much more then ribosomal proteins)
