HMM Summary Page: TIGR01733

Functionamino acid adenylation domain
Trusted Cutoff317.40
Domain Trusted Cutoff317.40
Noise Cutoff254.65
Domain Noise Cutoff254.65
Isology Typesubfamily_domain
HMM Length409
AuthorSelengut J
Entry DateOct 31 2002 11:05AM
Last ModifiedFeb 14 2011 3:27PM
CommentThis model represents a domain responsible for the specific recognition of amino acids and activation as adenylyl amino acids. The reaction catalyzed is aa + ATP -> 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, PF00550) 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, PF00668) which catalyzes the ligation of two amino acid thiol-esters from neighboring modules. This domain is a subset of the AMP-binding domain found in Pfam (PF00501) which also hits substrate--CoA ligases and luciferases. Sequences scoring in between trusted and noise for this model may be ambiguous as to whether they activate amino acids or other molecules lacking an alpha amino group.
ReferencesRN [1] RM PMID: 10021423 RT How do peptide synthetases generate structural diversity? RA Konz D, Marahiel MA. RL Chem Biol. 1999 Feb;6(2):R39-48. Review. DR HAMAP; MF_00593; 52 of 53