title: Structure of proline 3-hydroxylase. Evolution of the family of 2-oxoglutarate dependent oxygenases.
abstract: Iron (II)/2-oxoglutarate (2-OG)-dependent oxygenases catalyse oxidative reactions in a range of metabolic processes including the hydroxylation of proline and lysine residues during the post-translational modification of collagen. 2-OG oxygenases commonly require ascorbate for full activity. In the vitamin C deficient disease, scurvy, reduced activity of 2-OG oxygenases results in impaired formation of collagen. Here we report the crystal structure of bacterial proline 3-hydroxylase from Streptomyces sp., an enzyme which hydroxylates proline at position 3, the first of a 2-OG oxygenase catalysing oxidation of a free alpha-amino acid. Structures were obtained for the enzyme in the absence of iron (to 2.3A resolution, R=20.2%, Rfree=25.3%) and that complexed to iron (II) (to 2.4A resolution, R=19.8%, Rfree=22.6%). The structure contains conserved motifs present in other 2-OG oxygenases including a 'jelly roll' beta strand core and residues binding iron and 2-oxoglutarate, consistent with divergent evolution within the extended family. The structure differs significantly from many other 2-OG oxygenases in possessing a discrete C-terminal helical domain. Analysis of the structure suggests a model for proline binding and a mechanism for uncoupling of proline and 2-OG turnover.
authors.affiliation: The Dyson Perrins Laboratory and the Oxford Centre for Molecular Sciences, Oxford, UK.
authors.forename: I J
authors.initials: IJ
authors.lastname: Clifton
authors.forename: L C
authors.initials: LC
authors.lastname: Hsueh
authors.forename: J E
authors.initials: JE
authors.lastname: Baldwin
authors.forename: K
authors.initials: K
authors.lastname: Harlos
authors.forename: C J
authors.initials: CJ
authors.lastname: Schofield
mesh_terms: D000595:Amino Acid Sequence; D001665:Binding Sites; D018360:Crystallography, X-Ray; D019143:Evolution, Molecular; D007656:Ketoglutaric Acids / Q000378:metabolism; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011393:Procollagen-Proline Dioxygenase / Q000737:chemistry* / Q000378:metabolism; D011392:Proline / Q000378:metabolism; D011487:Protein Conformation; D017386:Sequence Homology, Amino Acid
chemical_list: D007656:Ketoglutaric Acids; D011392:Proline; D011393:Procollagen-Proline Dioxygenase; C030606:proline, 2-oxoglutarate 3-dioxygenase