Reactome: A Curated Pathway Database

Peptide chain elongation (R-HSA-156902) [Homo sapiens]


The mechanism of a peptide bond requires the movement of three protons. First the deprotonation of the ammonium ion generates a reactive amine, allowing a nucleophilic attack on the carbonyl group. This is followed by the loss of a proton from the reaction intermediate, only to be taken up by the oxygen on the leaving group (from the end of the amino acid chain bound to the tRNA in the P-site). The peptide bond formation results in the net loss of one water molecule, leaving a deacylated-tRNA in the P-site, and a nascent polypeptide chain one amino acid larger in the A-site.
For the purpose of illustration, the figures used in the section show one amino acid being added to a peptidyl-tRNA with a growing peptide chain.

Additional Information
Compartment cytosol
Cross References
Database Identifier
BioModels Database BIOMD0000000293
Literature References
pubMedId Title Journal Year
12297040 The path to perdition is paved with protons Cell 2002