BIO206H5 Lecture Notes - Lecture 15: Chief Operating Officer, Gif, Transferase
Document Summary
Ef-tu is single polypeptide made up of 3 distinct domains. Domains are globular in nature which fold independently of eachother. Gtp molecule is bound in domain 1. H-bond network, hydrophibic, van-der walls allow for trna binding site on ef- Tu protein binds to acceptor strand of trna. Ef-tu/aa-trna/gtp: substrate part of bacterial ribosomal complex: binds trna. Latch opens trna released hydrolysis causes change in shape of switch helix. Gdp released (ef-ts) ready for new gtp and charged trna. Bond between p-site aa and trna is transferred to amino group of a-site amino acid: peptide bond formed, trna is displaced, no cofactors (high energy bond) small subunit shift with respect to large subunit. Stage 3: translocation small subunit moves 3 bases 5" (cid:224) 3" on mrna ribosome returned to original conformation: uncharged p-site trna, e site is expelled, polypeptide chain + trna, p site. Requires protein ef-g and gtp for energy.
