BIO206H5 Lecture Notes - Lecture 11: Peptidyl Transferase, Ester, 18S Ribosomal Rna
Document Summary
At the acceptor stem, there"s a conserved nucleotide sequence. If not present, it"s added onto trna molecule. It"s at the 3" end that the amino acid is added onto the trna molecule. Wobble hypothesis: the codon-anticodon recognition process is not 100% obedient to watson-crick base-pairing. It"s in the 3rd position (wobble position) that we have non-watson-crick base-paring possibilities. One of the reasons why this can happen is because the 1st and second positions are constrained, while the 3rd is not as constrained. Wobble can occur between h bonds of 1" on anticodon and 3" on mrna codon. Inosine, the derivative of adenine, can form multiple base pairing with a, c, u. it"ll recognize 3 different codons (gcu, gcc, gca). The base-pairing rules is less rigid as a result of inosine. G-u base-pairing: only has 2 hydrogen bonds. Only g c base pair have 3 h bonds; the rest have 2. Inosine can base-pair with c, u or a trna charging:
