BIOL 2000 Lecture Notes - Positron, World Federation Of Trade Unions, Peptidyl Transferase
Document Summary
A site- decoding center: aminoacyl, binding site for aminoacylated. P site: peptidyl, trna has a peptide attached at this site. E site: exit site, after trna has delivered amino acid it comes here. 1) binding of the mrna to the small subunit (ssu) 2) recognition of a start codon: usually aug, utilizes a specialized initiator trna. Methionine is a standard amino acid with formyl group. 3) requires protein translation factors called initiation factors: not ribosomal proteins, used exclusively for initiation. In prokaryotes, a sequence upstream of an aug start codon defines the start site by binding to the small subunit of the ribosome. Dalgarno sequence at 3" end of small subunit rrna (16s rrna) The 16s rrna base pairs to this sequence. Anti-shine-dalgarno is the sequence on the small subunit. 1) keep subunits sperated: if= initation factors, large comes in at the end, bind charges subunit. 2) recruit the initiator trna and positron it at a start codon.
