IUBMB Enzyme Nomenclature


Accepted name: ferric salmochelin esterase

Reaction: (1) iron(III)-[diglucosyl-enterobactin] complex + H2O = iron(III)-[salmochelin S2] complex
(2) iron(III)-[monoglucosyl-enterobactin] complex + H2O = iron(III)-[monoglucosyl-(2,3-dihydroxybenzoylserine)3] complex
(3) iron(III)-[salmochelin S2] complex + H2O = iron(III)-[diglucosyl-(2,3-dihydroxybenzoylserine)2] complex + N-(2,3-dihydroxybenzoyl)-L-serine
(4) iron(III)-[salmochelin S2] complex + H2O = iron(III)-[salmochelin S1] complex + salmochelin SX
(5) iron(III)-[monoglucosyl-(2,3-dihydroxybenzoylserine)3] complex + H2O = iron(III)-[salmochelin S1] complex + N-(2,3-dihydroxybenzoyl)-L-serine
(6) iron(III)-[diglucosyl-(2,3-dihydroxybenzoylserine)2] complex + H2O = iron(III)-[salmochelin SX] complex + salmochelin SX

Glossary: salmochelin S2 = O-3-{O-3-[N-(2,3-dihydroxybenzoyl)-C-5-deoxy-β-D-glucosyl-L-seryl]-N-(2,3-dihydroxybenzoyl)-C-5-deoxy-β-D-glucosyl-L-seryl}-N-(2,3-dihydroxybenzoyl)-L-serine
salmochelin S1 = O-3-[N-(2,3-dihydroxybenzoyl)-L-seryl]-N-(C-5-deoxy-β-D-glucosyl-2,3-dihydroxybenzoyl)-L-serine
monoglucosyl-enterobactin = N-(2,3-dihydroxybenzoyl)-O-[N-(2,3-dihydroxybenzoyl)-O-[N-(5-β-D-glucopyranosyl-2,3-dihydroxybenzoyl)-L-seryl]-L-seryl]-L-serine-[3→1(3)]-lactone = mono-C-glucosyl-enterobactin = salmochelin MGE
diglucosyl-enterobactin = N-(2,3-dihydroxybenzoyl)-O-[N-(5-β-D-glucopyranosyl-2,3-dihydroxybenzoyl)-O-[N-(5-β-D-glucopyranosyl-2,3-dihydroxybenzoyl)-L-seryl]-L-seryl]-L-serine-[3→1(3)]-lactone = salmochelin S4 = di-C-glucosyl-enterobactin
salmochelin SX = N-(C-5-deoxy-β-D-glucosyl-2,3-dihydroxybenzoyl)-L-serine

Other name(s): iroD (gene name)

Systematic name: iron(III)-salmochelin complex hydrolase

Comments: This bacterial enzyme is present in pathogenic Salmonella species, uropathogenic and avian pathogenic Escherichia coli strains, and certain Klebsiella strains. The enzyme acts on iron(III)-bound enterobactin and C-glucosylated derivatives known as salmochelins. Unlike EC, apo-salmochelin esterase (IroE), IroD prefers iron(III)bound siderophores as substrates, and is assumed to act after the iron-siderophore complexes are imported into the cell. It catalyses several hydrolytic reactions, producing a mixture of iron(III)-[N-(2,3-dihydroxybenzoyl)-L-serine] complex and salmochelin SX.

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


1. Lin, H., Fischbach, M.A., Liu, D.R. and Walsh, C.T. In vitro characterization of salmochelin and enterobactin trilactone hydrolases IroD, IroE, and Fes. J. Am. Chem. Soc. 127 (2005) 11075-11084. [PMID: 16076215]

[EC created 2019]

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