1is7
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Crystal structure of rat GTPCHI/GFRP stimulatory complex
OverviewOverview
In the presence of phenylalanine, GTP cyclohydrolase I feedback regulatory protein (GFRP) forms a stimulatory 360-kDa complex with GTP cyclohydrolase I (GTPCHI), which is the rate-limiting enzyme in the biosynthesis of tetrahydrobiopterin. The crystal structure of the stimulatory complex reveals that the GTPCHI decamer is sandwiched by two GFRP homopentamers. Each GFRP pentamer forms a symmetrical five-membered ring similar to beta-propeller. Five phenylalanine molecules are buried inside each interface between GFRP and GTPCHI, thus enhancing the binding of these proteins. The complex structure suggests that phenylalanine-induced GTPCHI x GFRP complex formation enhances GTPCHI activity by locking the enzyme in the active state.
About this StructureAbout this Structure
1IS7 is a Protein complex structure of sequences from Rattus norvegicus with and as ligands. Active as GTP cyclohydrolase I, with EC number 3.5.4.16 Full crystallographic information is available from OCA.
ReferenceReference
Crystal structure of the stimulatory complex of GTP cyclohydrolase I and its feedback regulatory protein GFRP., Maita N, Okada K, Hatakeyama K, Hakoshima T, Proc Natl Acad Sci U S A. 2002 Feb 5;99(3):1212-7. Epub 2002 Jan 29. PMID:11818540
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