|Superclasses:||Reactions Classified By Conversion Type → Simple Reactions → Chemical Reactions|
|Reactions Classified By Substrate → Small-Molecule Reactions|
EC Number: 18.104.22.168
The reaction direction shown, that is, A + B ↔ C + D versus C + D ↔ A + B, is in accordance with the Enzyme Commission system.
Most BioCyc compounds have been protonated to a reference pH value of 7.3, and some reactions have been computationally balanced for hydrogen by adding free protons. Please see the PGDB Concepts Guide for more information.
Mass balance status: Balanced.
Enzyme Commission Primary Name: GTP cyclohydrolase I
Enzyme Commission Synonyms: GTP cyclohydrolase, guanosine triphosphate cyclohydrolase, guanosine triphosphate 8-deformylase, dihydroneopterin triphosphate synthase, GTP 8-formylhydrolase
Enzyme Commission Summary:
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 22.214.171.124 (sepiapterin reductase) and EC 126.96.36.199 (6-pyruvoyltetrahydropterin synthase) [Supangat05].
Burg68: Burg AW, Brown GM (1968). "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(9);2349-58. PMID: 4296838
Supangat05: Supangat S, Choi YK, Park YS, Son D, Han CD, Lee KH (2005). "Expression, purification, crystallization and preliminary X-ray analysis of sepiapterin reductase from Chlorobium tepidum." Acta Crystallogr Sect F Struct Biol Cryst Commun 61(Pt 2);202-4. PMID: 16510994
Wolf69: Wolf WA, Brown GM (1969). "The biosynthesis of folic acid. X. Evidence for an Amadori rearrangement in the enzymatic formation of dihydroneopterin triphosphate from GTP." Biochim Biophys Acta 192(3);468-78. PMID: 4904679
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