BIO206H5 Lecture Notes - Lecture 16: Kozak Consensus Sequence, Aminoacyl-Trna, World Federation Of Trade Unions
Document Summary
Accuracy at which the correct amino acid is charged onto its cognate trna. Ef-tu can"t bind and pull out the trna now; if precise fit does not occur, ef-tu leaves the ribosome with the charged trna associated with it; Need binding, the transpeptidation, then translocation; this is achieved by having many overlapping binding sites for these elongation factors. Overall process resembles prokaryotic initiation: more initiation factors (eif-n) > 10, trnaimet differs from regular trnamet but met is not formylated (not an f-met) Stage 2: eif-1a, eif-3, 40s ribosome, mrna, trnaimet + eif-2. Another set of initiation factors are designated as eif4e and eif4g (5" cap binding proteins); messenger rna is recognized by the ribosome by this. Catalytic centre is the 28s ribosomal rna (ribozyme) Proteins are made on polysomes: multiple ribosomes translating same mrna (polyribosomes, both prokaryotes and eukaryotes, tandem arrangement. Next ribosome joins after first clears initiation site. Messenger rna can have multiple ribosomes, producing protein simultaneously.
