Reactome | GCH1 reduces GTP to dihydroneopterin triphosphate

GCH1 reduces GTP to dihydroneopterin triphosphate

Stable Identifier

R-HSA-1474146

Type

Reaction [transition]

Species

Homo sapiens

Compartment

cytosol

ReviewStatus

5/5

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GCH1 reduces GTP to dihydroneopterin triphosphate

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The first and rate-limiting enzyme in tetrahydrobiopterin de novo biosynthesis is GTP cyclohydrolase I (GCH1, GTPCHI). Three different isoforms are produced but only isoform 1 is functionally active (Gütlich et al. 1994). GCH1 is functional as a homodecamer. First, a monomer of GCH1 forms a dimer. Then five dimers arrange into a ring-like structure to form the homodecamer (Nar et al. 1995).

Literature References

PubMed ID	Title	Journal	Year
7663943	Atomic structure of GTP cyclohydrolase I Nar, H, Schmid, C, Bacher, A, Weinkauf, S, Meining, W, Huber, R	Structure	1995
8068008	Human GTP cyclohydrolase I: only one out of three cDNA isoforms gives rise to the active enzyme Rücknagel, KP, Rödl, W, Ziegler, I, Bacher, A, Gütlich, M, Werner, T, Jaeger, E	Biochem J	1994