In about half the polypeptides, the methionine at the terminus is removed by an aminopeptidase, which creates a new terminus from R2 (originally the second amino acid incorporated into the chain). When both steps are necessary, they occur sequentially. The removal reaction(s) occur rather rapidly when the nascent polypeptide chain has reached a length of 15 amino acids.
#Unit 3. Fundamental Processes#Prokaryotic Translation#Part B Pointers
