Because of a lapse in government funding, the information on this website may not be up to date, transactions submitted via the website may not be processed, and the agency may not be able to respond to inquiries until appropriations are enacted. The NIH Clinical Center (the research hospital of NIH) is open. For more details about its operating status, please visit cc.nih.gov. Updates regarding government operating status and resumption of normal operations can be found at opm.gov.

NLM Logo

GTP Cyclohydrolase MeSH Descriptor Data 2026


MeSH Heading
GTP Cyclohydrolase
Tree Number(s)
D08.811.277.151.300
Unique ID
D006136
RDF Unique Identifier
http://id.nlm.nih.gov/mesh/D006136
Scope Note
(GTP cyclohydrolase I) or GTP 7,8-8,9-dihydrolase (pyrophosphate-forming) (GTP cyclohydrolase II). An enzyme group that hydrolyzes the imidazole ring of GTP, releasing carbon-8 as formate. Two C-N bonds are hydrolyzed and the pentase unit is isomerized. This is the first step in the synthesis of folic acid from GTP. EC 3.5.4.16 (GTP cyclohydrolase I) and EC 3.5.4.25 (GTP cyclohydrolase II).
Entry Term(s)
7,8-Dihydroneopterintriphosphate Synthetase
GTP 8-Formylhydrolase
GTP Cyclohydrolase I
GTP Cyclohydrolase II
GTP Dihydrolase
GTP Ring-Opening Enzyme
Registry Numbers
EC 3.5.4.16
0
CAS Type 1 Name
GTP 7,8-8,9-dihydrolase
Previous Indexing
Aminohydrolases (1974)
Guanosine Triphosphate (1974)
Public MeSH Note
91; was see under AMINOHYDROLASES 1975-90
History Note
91(75); was see under AMINOHYDROLASES 1975-90
Date Introduced
1991/01/01
Last Updated
2003/07/09
GTP Cyclohydrolase Preferred
GTP Cyclohydrolase I Narrower
GTP Cyclohydrolase II Narrower
page delivered in 0.121s