title: Structural analysis of cofactor binding for a prolyl 4-hydroxylase from the pathogenic bacterium Bacillus anthracis.
abstract: The prolyl 4-hydroxylases (P4Hs) are mononuclear nonheme iron enzymes that catalyze the formation of 4R-hydroxyproline from many different substrates, with various biological implications. P4H is a key player in collagen accumulation, which has implications in fibrotic disorders. The stabilization of collagen triple-helical structure via prolyl hydroxylation is the rate-limiting step in collagen biosynthesis, and therefore P4H has been extensively investigated as a potential therapeutic target of fibrotic disease. Understanding how these enzymes recognize cofactors and substrates is important and will aid in the future design of inhibitors of P4H. In this article, X-ray crystal structures of a metallocofactor- and α-ketoglutarate (αKG)-bound form of P4H from Bacillus anthracis (BaP4H) are reported. Structures of BaP4H were solved at 1.63 and 2.35 Å resolution and contained a cadmium ion and αKG bound in the active site. The αKG-Cd-BaP4H ternary complex reveals conformational changes of conserved residues upon the binding of metal ion and αKG, resulting in a closed active-site configuration required for dioxygen, substrate binding and catalysis.
authors.affiliation: Department of Chemistry, University of Iowa, Iowa City, IA 52242, USA.
authors.forename: Nicholas J
authors.initials: NJ
authors.lastname: Schnicker
authors.affiliation: Department of Chemistry, University of Iowa, Iowa City, IA 52242, USA.
authors.forename: Mishtu
authors.initials: M
authors.lastname: Dey
mesh_terms: D000881:Anthrax / Q000382:microbiology*; D001408:Bacillus anthracis / Q000737:chemistry* / Q000201:enzymology* / Q000378:metabolism; D020134:Catalytic Domain; D003067:Coenzymes / Q000378:metabolism; D018360:Crystallography, X-Ray; D006801:Humans; D007656:Ketoglutaric Acids / Q000378:metabolism; D008958:Models, Molecular; D064828:Prolyl Hydroxylases / Q000737:chemistry* / Q000378:metabolism*; D011485:Protein Binding; D013379:Substrate Specificity
chemical_list: D003067:Coenzymes; D007656:Ketoglutaric Acids; D064828:Prolyl Hydroxylases
keywords: Fe2+/α-ketoglutarate-dependent dioxygenase; crystal structure; nonheme iron enzyme; prolyl 4-hydroxylase