InterPro: IPR010071 Amino acid adenylation

This entry represents a domain responsible for the specific recognition of amino acids and activation as adenylyl amino acids. The reaction catalysed is aa + ATP to aa-AMP + PPi. These domains are usually found as components of multi-domain non-ribosomal peptide synthetases and are usually called 'A-domains' in that context (for a review, see [1]). A-domains are almost invariably followed by 'T-domains' (thiolation domains, IPR006163) to which the amino acid adenylate is transferred as a thiol-ester to a bound pantetheine cofactor with the release of AMP (these are also called peptide carrier proteins, or PCPs. When the A-domain does not represent the first module (corresponding to the first amino acid in the product molecule) it is usually preceded by a 'C-domain' (condensation domain, IPR001242) which catalyses the ligation of two amino acid thiol-esters from neighbouring modules. This domain is a subset of the AMP-binding domain, which also hits substrate--CoA ligases and luciferases.