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- ***********************************
- * GTP cyclohydrolase I signatures *
- ***********************************
-
- GTP cyclohydrolase I (EC 3.5.4.16) catalyzes the biosynthesis of formic acid
- and dihydroneopterin triphosphate from GTP. This reaction is the first step in
- the biosynthesis of tetrahydrofolate in prokaryotes, of tetrahydrobiopterin in
- vertebrates, and of pteridine-containing pigments in insects.
-
- GTP cyclohydrolase I is a protein of from 190 to 250 amino acid residues. The
- comparison of the sequence of the enzyme from bacterial and eukaryotic sources
- shows that the structure of this enzyme has been extremely well conserved
- throughout evolution [1,2].
-
- As signature patterns we selected two conserved regions. The first contains a
- perfectly conserved tetrapeptide that could be part of the active site of the
- enzyme.
-
- -Consensus pattern: [DE](2)-[LIVM](2)-x-[LIVM]-[KR]-D-[LIVM]-x(3)-S-x-C-E-H-H
- -Sequences known to belong to this class detected by the pattern: ALL.
- -Other sequence(s) detected in SWISS-PROT: NONE.
-
- -Consensus pattern: R-x-Q-[LIVM]-Q-E-R-[LIVM]-T
- -Sequences known to belong to this class detected by the pattern: ALL.
- -Other sequence(s) detected in SWISS-PROT: NONE.
-
- -Last update: October 1993 / First entry.
-
- [ 1] Babitzke P., Gollnick P., Yanofsky C.
- J. Bacteriol. 174:2059-2064(1992).
- [ 2] Togari A., Ichinose H., Matsumoto S., Fujita K., Nagatsu T.
- Biochem. Biophys. Res. Commun. 187:359-365(1992).
-