Crystal structure and refinement of cytochrome P450terp at 2.3 A resolution

J Mol Biol. 1994 Mar 4;236(4):1169-85. doi: 10.1016/0022-2836(94)90019-1.


Cytochrome P450terp is a class I (mitochondrial/bacterial) P450 that catalyzes the hydroxylation of alpha-terpineol as part of the catabolic assimilation of this compound by a pseudomonad species. Crystals grown from the purified protein have the symmetry of space group P6(1)22, and cell dimensions a = b = 69.4 A, c = 456.6 A, alpha = beta = 90 degrees, gamma = 120 degrees. Diffraction data were collected at the Cornell High Energy Synchrotron Source, and the structure of P450terp was solved by a combination of molecular replacement and multiple isomorphous replacement techniques. A model of P450terp was built and refined against native data, to an R-factor of 18.9% for data with I > or = sigma(I) between 6.0 A and 2.3 A resolution. This model contains 412 of the 428 P450terp amino acid residues; the loop between helices F and G is disordered in the crystal. While the overall fold of P450terp is very similar to that of P450cam, only three-quarters of the C alpha positions can be superimposed, to a root-mean-square deviation of only 1.87 A. The mode of substrate binding by P450terp can be predicted, and probable substrate contact residues identified. The heme environment and side-chain positions in the adjacent I-helix suggest possible modes of proton delivery in the catalytic cycle of the enzyme.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Binding Sites / genetics
  • Camphor 5-Monooxygenase
  • Catalysis
  • Crystallization
  • Crystallography, X-Ray
  • Cytochrome P-450 Enzyme System / chemistry*
  • Cytochrome P-450 Enzyme System / genetics
  • Heme / chemistry
  • Mixed Function Oxygenases / chemistry*
  • Mixed Function Oxygenases / genetics
  • Models, Molecular
  • Molecular Sequence Data
  • Molecular Structure
  • Protein Conformation
  • Protein Structure, Secondary
  • Protein Structure, Tertiary
  • Sequence Homology, Amino Acid


  • Heme
  • Cytochrome P-450 Enzyme System
  • Mixed Function Oxygenases
  • terpineol hydroxylase
  • Camphor 5-Monooxygenase