1is7
Crystal structure of rat GTPCHI/GFRP stimulatory complex
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| , resolution 2.8Å | |||||||
|---|---|---|---|---|---|---|---|
| Ligands: | and | ||||||
| Activity: | GTP cyclohydrolase I, with EC number 3.5.4.16 | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
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. 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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