EC |
2.8.1.12 |
Accepted name: |
molybdopterin synthase |
Reaction: |
cyclic pyranopterin phosphate + 2 [molybdopterin-synthase sulfur-carrier protein]-Gly-NH-CH2-C(O)SH + H2O = molybdopterin + 2 molybdopterin-synthase sulfur-carrier protein |
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For diagram of MoCo biosynthesis, click here |
Glossary: |
molybdopterin = H2Dtpp-mP = {[(5aR,8R,9aR)-2-amino-4-oxo-6,7-bis(sulfanyl-κS)-1,5,5a,8,9a,10-hexahydro-4H-pyrano[3,2-g]pteridin-8-yl]methyl dihydrogenato(2-) phosphate}(dioxo)molybdate(2-)
cyclic pyranopterin phosphate = cPMP = precursor Z = 8-amino-2,12,12-trihydroxy-4a,5a,6,9,11,11a,12,12a-octahydro[1,3,2]dioxaphosphinino[4′,5′:5,6]pyrano[3,2-g]pteridin-10(4H)-one 2-oxide = 8-amino-2,12,12-trihydroxy-4,4a,5a,6,9,10,11,11a,12,12a-decahydro-[1,3,2]dioxaphosphinino[4′,5′:5,6]pyrano[3,2-g]pteridine 2-oxide |
Other name(s): |
MPT synthase |
Systematic name: |
thiocarboxylated molybdopterin synthase:cyclic pyranopterin phosphate sulfurtransferase |
Comments: |
Catalyses the synthesis of molybdopterin from cyclic pyranopterin monophosphate. Two sulfur atoms are transferred to cyclic pyranopterin monophosphate in order to form the characteristic ene-dithiol group found in the molybdenum cofactor. Molybdopterin synthase consists of two large subunits forming a central dimer and two small subunits (molybdopterin-synthase sulfur-carrier proteins) that are thiocarboxylated at the C-terminus by EC 2.8.1.11, molybdopterin synthase sulfurtransferase. The reaction occurs in prokaryotes and eukaryotes. |
Links to other databases: |
BRENDA, EXPASY, KEGG, MetaCyc, PDB |
References: |
1. |
Daniels, J.N., Wuebbens, M.M., Rajagopalan, K.V. and Schindelin, H. Crystal structure of a molybdopterin synthase-precursor Z complex: insight into its sulfur transfer mechanism and its role in molybdenum cofactor deficiency. Biochemistry 47 (2008) 615–626. [DOI] [PMID: 18092812] |
2. |
Wuebbens, M.M. and Rajagopalan, K.V. Mechanistic and mutational studies of Escherichia coli molybdopterin synthase clarify the final step of molybdopterin biosynthesis. J. Biol. Chem. 278 (2003) 14523–14532. [DOI] [PMID: 12571226] |
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[EC 2.8.1.12 created 2011] |
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EC
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4.1.99.18
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Transferred entry: | cyclic pyranopterin phosphate synthase. Now known to be catalysed by the combined effort of EC 4.1.99.22, GTP 3,8-cyclase, and EC 4.6.1.17, cyclic pyranopterin monophosphate synthase
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[EC 4.1.99.18 created 2011, deleted 2016] |
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EC |
4.6.1.17 |
Accepted name: |
cyclic pyranopterin monophosphate synthase |
Reaction: |
(8S)-3′,8-cyclo-7,8-dihydroguanosine 5′-triphosphate = cyclic pyranopterin phosphate + diphosphate |
Other name(s): |
MOCS1B (gene name); moaC (gene name); cnx3 (gene name) |
Systematic name: |
(8S)-3′,8-cyclo-7,8-dihydroguanosine 5′-triphosphate lyase (cyclic pyranopterin phosphate-forming) |
Comments: |
The enzyme catalyses an early step in the biosynthesis of the molybdenum cofactor (MoCo). In bacteria and plants the reaction is catalysed by MoaC and Cnx3, respectively. In mammals the reaction is catalysed by the MOCS1B domain of the bifuctional MOCS1 protein, which also catalyses EC 4.1.99.22, GTP 3′,8-cyclase. |
Links to other databases: |
BRENDA, EXPASY, KEGG, MetaCyc, PDB |
References: |
1. |
Rieder, C., Eisenreich, W., O'Brien, J., Richter, G., Götze, E., Boyle, P., Blanchard, S., Bacher, A. and Simon, H. Rearrangement reactions in the biosynthesis of molybdopterin - an NMR study with multiply 13C/15N labelled precursors. Eur. J. Biochem. 255 (1998) 24–36. [DOI] [PMID: 9692897] |
2. |
Wuebbens, M.M. and Rajagopalan, K.V. Investigation of the early steps of molybdopterin biosynthesis in Escherichia coli through the use of in vivo labeling studies. J. Biol. Chem. 270 (1995) 1082–1087. [DOI] [PMID: 7836363] |
3. |
Hover, B.M., Tonthat, N.K., Schumacher, M.A. and Yokoyama, K. Mechanism of pyranopterin ring formation in molybdenum cofactor biosynthesis. Proc. Natl. Acad. Sci. USA 112 (2015) 6347–6352. [DOI] [PMID: 25941396] |
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[EC 4.6.1.17 created 2011 as EC 4.1.99.18, part transferred 2016 to EC 4.6.1.17] |
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