IUBMB Enzyme Nomenclature


Accepted name: L-cysteine—[L-cysteinyl-carrier protein] ligase

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

Other name(s): pchE (gene name); pchF (gene name); angR (gene name)

Systematic name: L-cysteine:[L-cysteinyl-carrier protein] ligase (AMP-forming)

Comments: The adenylation domain of the enzyme catalyses the activation of L-cysteine to (L-cysteinyl)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. Quadri, L.E., Keating, T.A., Patel, H.M. and Walsh, C.T. Assembly of the Pseudomonas aeruginosa nonribosomal peptide siderophore pyochelin: In vitro reconstitution of aryl-4, 2-bisthiazoline synthetase activity from PchD, PchE, and PchF. Biochemistry 38 (1999) 14941-14954. [PMID: 10555976]

[EC created 2021]

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