A Site

∞ generated and posted on 2015.12.27 ∞

Place where aminoacyl tRNAs bind to the ribosome during translation.

The A Site is the ribosome location of binding to charged tRNAs, that is, aminoacyl tRNAs which bring individual amino acids to the growing peptide chain during the process of translation, i.e., protein biosynthesis.

Amino acids and associated tRNAs (the latter with their anticodons) enter the ribosome during translation at the A site. The tRNA then proceeds to the P site and then the E site before leaving the ribosome. These various movements occur in association with a ratcheting of the mRNA through the ribosome.

The 'A' in A site of course stands for Amino acid and/or Aminoacyl.