| EC |
3.5.4.16 |
| Accepted name: |
GTP cyclohydrolase I |
| Reaction: |
GTP + H2O = formate + 7,8-dihydroneopterin 3′-triphosphate |
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For diagram of folate biosynthesis (early stages), click here |
| Glossary: |
7,8-dihydroneopterin 3′-triphosphate = 6-[(1S,2R)-1,2-dihydroxy-3-triphosphooxypropyl]-7,8-dihydropterin |
| Other name(s): |
GTP cyclohydrolase; guanosine triphosphate cyclohydrolase; guanosine triphosphate 8-deformylase; dihydroneopterin triphosphate synthase; GTP 8-formylhydrolase |
| Systematic name: |
GTP 7,8-8,9-dihydrolase |
| Comments: |
The reaction involves hydrolysis of two C-N bonds and isomerization of the pentose unit; the recyclization may be non-enzymic. This enzyme is involved in the de novo synthesis of tetrahydrobiopterin from GTP, with the other enzymes involved being EC 1.1.1.153 [sepiapterin reductase (L-erythro-7,8-dihydrobiopterin-forming)] and EC 4.2.3.12 (6-pyruvoyltetrahydropterin synthase) [3]. |
| Links to other databases: |
BRENDA, EXPASY, Gene, KEGG, MetaCyc, PDB, CAS registry number: 37289-19-3 |
| References: |
| 1. |
Burg, A.W. and Brown, G.M. The biosynthesis of folic acid. 8. Purification and properties of the enzyme that catalyzes the production of formate from carbon atom 8 of guanosine triphosphate. J. Biol. Chem. 243 (1968) 2349–2358. [PMID: 4296838] |
| 2. |
Wolf, W.A. and Brown, G.M. The biosynthesis of folic acid. X. Evidence for an Amadori rearrangement in the enzymatic formation of dihydroneopterin triphosphate from GTP. Biochim. Biophys. Acta 192 (1969) 468–478. [DOI] [PMID: 4904679] |
| 3. |
Supangat, S., Choi, Y.K., Park, Y.S., Son, D., Han, C.D. and Lee, K.H. Expression, purification, crystallization and preliminary X-ray analysis of sepiapterin reductase from Chlorobium tepidum. Acta Crystallogr. Sect. F Struct. Biol. Cryst. Commun. 61 (2005) 202–204. [DOI] [PMID: 16510994] |
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| [EC 3.5.4.16 created 1972] |
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