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GTP cyclohydrolase 1 (dopa-responsive dystonia)
PDB rendering based on 1fb1.
Available structures: 1fb1, 1is7, 1is8, 1wpl
Identifiers
Symbols	GCH1; DYT5; GCH; GTP-CH-1; GTPCH1
External IDs	OMIM: 600225 MGI: 95675 HomoloGene: 132
EC number	3.5.4.16
Gene ontology Molecular function: • GTP cyclohydrolase I activity • protein binding • hydrolase activity Cellular component: • cytoplasm Biological process: • L-phenylalanine catabolic process • tetrahydrobiopterin biosynthetic process • nitric oxide biosynthetic process • aromatic compound biosynthetic process • neurotransmitter metabolic process
RNA expression pattern
More reference expression data
Orthologs
	Human	Mouse
Entrez	2643	14528
Ensembl	ENSG00000131979	ENSMUSG00000037580
Uniprot	P30793	Q3U7P6
Refseq	NM_000161 (mRNA) NP_000152 (protein)	NM_008102 (mRNA) NP_032128 (protein)
Location	Chr 14: 54.38 - 54.44 Mb	Chr 14: 46.08 - 46.11 Mb
Pubmed search	[1]	[2]

GTP cyclohydrolase I (GTP 7,8-8,9-dihydrolase, EC 3.5.4.16) is an enzyme that is part of the folate and biopterin biosynthesis pathways. It is responsible for the hydrolysis of guanosine triphosphate (GTP) to form 7,8-dihydroneopterin 3'-triphosphate.

This gene encodes a member of the GTP cyclohydrolase family. The encoded protein is the first and rate-limiting enzyme in tetrahydrobiopterin (BH4) biosynthesis, catalyzing the conversion of GTP into 7,8-dihydroneopterin triphosphate. BH4 is an essential cofactor required by aromatic amino acid hydroxylases as well as nitric oxide synthases. Mutations in this gene are associated with malignant hyperphenylalaninemia and dopa-responsive dystonia. Several alternatively spliced transcript variants encoding different isoforms have been described; however, not all variants give rise to a functional enzyme.¹

The reaction performed by GTP cyclohydrolase I. The important carbons relative to the transformation are numbered for reference.

References

1. ^ "Entrez Gene: GCH1 GTP cyclohydrolase 1 (dopa-responsive dystonia)".

• Voet, Judith G.; Voet, Donald (2004). Biochemistry. New York: J. Wiley & Sons. ISBN 0-471-39223-5. 
• EC 3.5.4.16 IUBMB Enzyme Nomenclature

External links

• MeSH GTP+Cyclohydrolase+I

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Wikipedia content modification information:

• This page was last modified on 28 October 2008, at 05:33.

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