title: Preparation and crystallization of the stimulatory and inhibitory complexes of GTP cyclohydrolase I and its feedback regulatory protein GFRP.
abstract: Mammalian GTP cyclohydrolase I is a decameric enzyme in the first and rate-limiting step in the biosynthesis of tetrahydrobiopterin, which is an essential cofactor for enzymes producing neurotransmitters such as catecholamines and for nitric oxide synthases. The enzyme is dually regulated by its feedback regulatory protein GFRP in the presence of its stimulatory effector phenylalanine and its inhibitory effector biopterin. Here, both the stimulatory and inhibitory complexes of rat GTP cyclohydrolase I bound to GFRP were crystallized by vapour diffusion. Diffraction data sets at resolutions of 3.0 and 2.64 A were collected for the stimulatory and inhibitory complexes, respectively. Each complex consists of two GTPCHI pentamer rings and two GFRP pentamer rings, with pseudo-52 point-group symmetry.
authors.affiliation: Department of Molecular Biology, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara 630-0101, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Maita
authors.forename: K
authors.initials: K
authors.lastname: Okada
authors.forename: S
authors.initials: S
authors.lastname: Hirotsu
authors.forename: K
authors.initials: K
authors.lastname: Hatakeyama
authors.forename: T
authors.initials: T
authors.lastname: Hakoshima
mesh_terms: D000818:Animals; D003460:Crystallization; D018360:Crystallography, X-Ray; D005246:Feedback; D006136:GTP Cyclohydrolase / Q000737:chemistry* / Q000378:metabolism; D047908:Intracellular Signaling Peptides and Proteins; D011487:Protein Conformation; D011506:Proteins / Q000737:chemistry* / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism
chemical_list: C491065:Gchfr protein, rat; D047908:Intracellular Signaling Peptides and Proteins; D011506:Proteins; D011994:Recombinant Proteins; D006136:GTP Cyclohydrolase