IUBMB Enzyme Nomenclature


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

For diagram of reaction 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–)
cPMP = cyclic pyranopterin monophosphate = 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; thiocarboxylated molybdopterin synthase:cyclic pyranopterin monophosphate sulfurtransferase

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, molybdopterin synthase sulfurtransferase. The reaction occurs in prokaryotes and eukaryotes.

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


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. [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. [PMID: 12571226]

[EC created 2011]

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