The structure of the organic hydroperoxide resistance protein from Deinococcus radiodurans. Do conformational changes facilitate recycling of the redox disulfide?
The three-dimensional structure of the organic hydroperoxide resistance protein (OHRP) from Deinococcus radiodurans as determined using single crystal xray diffraction techniques is reported. Comparison of the structure with that obtained for OHRP from Pseudomonas aeruginosa reveals that the polypeptide chain of OHRPs can adopt two significantly different conformations ("in" and "out") in the region of the active site disulfide moiety. It is postulated that the closed configuration is consistent with efficient catalysis of the reduction of organic hydroperoxides, whereas the open form is required for enzyme recycling. Comparison of the structures of OHRP and that of the osmotically induced protein C (OsmC) from Mycoplasma pneumoniae shows that OHRPs and OsmCs are structurally homologous, perhaps indicating related functions for the two families of proteins.
Meunier-Jamin
Cécile
C
Macromolecular Crystallography Group, European Synchrotron Radiation Facility, B.P. 220, F-38043 Grenoble Cedex, France.
Kapp
Ulrike
U
Leonard
Gordon A
GA
McSweeney
Seán
S
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry*; D003460:Crystallization; D034301:Deinococcus / Q000737:chemistry*; D004220:Disulfides / Q000737:chemistry; D029968:Escherichia coli Proteins / Q000737:chemistry; D008969:Molecular Sequence Data; D011487:Protein Conformation
D001426:Bacterial Proteins; D004220:Disulfides; D029968:Escherichia coli Proteins; C099394:osmC protein, E coli