Structure of proline 3-hydroxylase. Evolution of the family of 2-oxoglutarate dependent oxygenases

Eur J Biochem. 2001 Dec;268(24):6625-36. doi: 10.1046/j.0014-2956.2001.02617.x.


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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Binding Sites
  • Crystallography, X-Ray
  • Evolution, Molecular*
  • Ketoglutaric Acids / metabolism
  • Models, Molecular
  • Molecular Sequence Data
  • Procollagen-Proline Dioxygenase / chemistry*
  • Procollagen-Proline Dioxygenase / metabolism
  • Proline / metabolism
  • Protein Conformation
  • Sequence Homology, Amino Acid


  • Ketoglutaric Acids
  • Proline
  • Procollagen-Proline Dioxygenase
  • proline, 2-oxoglutarate 3-dioxygenase