EC |
4.99.1.4 |
Accepted name: |
sirohydrochlorin ferrochelatase |
Reaction: |
siroheme + 2 H+ = sirohydrochlorin + Fe2+ |
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For diagram of corrin and siroheme biosynthesis (part 2), click here |
Other name(s): |
CysG; Met8P; SirB; sirohydrochlorin ferro-lyase (incorrect) |
Systematic name: |
siroheme ferro-lyase (sirohydrochlorin-forming) |
Comments: |
This enzyme catalyses the third of three steps leading to the formation of siroheme from uroporphyrinogen III. The first step involves the donation of two S-adenosyl-L-methionine-derived methyl groups to carbons 2 and 7 of uroporphyrinogen III to form precorrin-2 (EC 2.1.1.107, uroporphyrin-III C-methyltransferase) and the second step involves an NAD+-dependent dehydrogenation to form sirohydrochlorin from precorrin-2 (EC 1.3.1.76, precorrin-2 dehydrogenase). In Saccharomyces cerevisiae, the last two steps are carried out by a single bifunctional enzyme, Met8p. In some bacteria, steps 1-3 are catalysed by a single multifunctional protein called CysG, whereas in Bacillus megaterium, three separate enzymes carry out each of the steps, with SirB being responsible for the above reaction. |
Links to other databases: |
BRENDA, EXPASY, Gene, KEGG, MetaCyc, PDB |
References: |
1. |
Schubert, H.L., Raux, E., Brindley, A.A., Leech, H.K., Wilson, K.S., Hill, C.P. and Warren, M.J. The structure of Saccharomyces cerevisiae Met8p, a bifunctional dehydrogenase and ferrochelatase. EMBO J. 21 (2002) 2068–2075. [DOI] [PMID: 11980703] |
2. |
Warren, M.J., Raux, E., Schubert, H.L. and Escalante-Semerena, J.C. The biosynthesis of adenosylcobalamin (vitamin B12). Nat. Prod. Rep. 19 (2002) 390–412. [PMID: 12195810] |
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[EC 4.99.1.4 created 2004] |
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