IUBMB Enzyme Nomenclature


Accepted name: L-alanine—[L-alanyl-carrier protein] ligase

Reaction: ATP + L-alanine + holo-[L-alanyl-carrier protein] = AMP + diphosphate + L-alanyl-[L-alanyl-carrier protein] (overall reaction)
(1a) ATP + L-alanine = diphosphate + (L-alanyl)adenylate
(1b) (L-alanyl)adenylate + holo-[L-alanyl-carrier protein] = AMP + L-alanyl-[L-alanyl-carrier protein]

Other name(s): ambB (gene name); phsB (gene name)

Systematic name: L-alanine:[L-alanyl-carrier protein] ligase (AMP-forming)

Comments: The adenylation domain of the enzyme catalyses the activation of L-alanine to (L-alanyl)adenylate, followed by the transfer of the activated compound to the free thiol of a phosphopantetheine arm of a peptidyl-carrier protein domain. The peptidyl-carrier protein domain may be part of the same protein, or of a different protein. This activity is often found as part of a larger non-ribosomal peptide synthase.

Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number:


1. Schwartz, D., Grammel, N., Heinzelmann, E., Keller, U. and Wohlleben, W. Phosphinothricin tripeptide synthetases in Streptomyces viridochromogenes Tu494. Antimicrob. Agents Chemother. 49 (2005) 4598-4607. [PMID: 16251301]

2. Rojas Murcia, N., Lee, X., Waridel, P., Maspoli, A., Imker, H.J., Chai, T., Walsh, C.T. and Reimmann, C. The Pseudomonas aeruginosa antimetabolite L -2-amino-4-methoxy-trans-3-butenoic acid (AMB) is made from glutamate and two alanine residues via a thiotemplate-linked tripeptide precursor. Front. Microbiol. 6 (2015) 170. [PMID: 25814981]

[EC created 2018]

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