GCH1 reduces GTP to dihydroneopterin triphosphate

Stable Identifier
R-HSA-1474146
Type
Reaction [transition]
Species
Homo sapiens
Compartment
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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
8068008 Human GTP cyclohydrolase I: only one out of three cDNA isoforms gives rise to the active enzyme

Gütlich, M, Jaeger, E, Rücknagel, KP, Werner, T, Rödl, W, Ziegler, I, Bacher, A

Biochem J 1994
7663943 Atomic structure of GTP cyclohydrolase I

Nar, H, Huber, R, Meining, W, Schmid, C, Weinkauf, S, Bacher, A

Structure 1995
Participants
Participates
Catalyst Activity

GTP cyclohydrolase I activity of GCH1 decamer [cytosol]

This event is regulated
Negatively by
Positively by
Regulator
Orthologous Events
Cross References
Rhea
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