Structure of the stress response protein DR1199 from Deinococcus radiodurans: a member of the DJ-1 superfamily.

The expression level of protein DR1199 is observed to increase considerably in the radio-resistant bacterium Deinococcus radiodurans following irradiation. This protein belongs to the DJ-1 superfamily, which includes proteins with diverse functions, such as the archaeal proteases PhpI and PfpI, the bacterial chaperone Hsp31 and hyperosmotic stress protein YhbO, and the human Parkinson's disease-related protein DJ-1. All members of the superfamily are oligomeric, and the oligomerization interface varies from protein to protein.

The crystal structure of a plant 3-ketoacyl-CoA thiolase reveals the potential for redox control of peroxisomal fatty acid beta-oxidation.

Crystal structures of peroxisomal Arabidopsis thaliana 3-ketoacyl-CoA thiolase (AtKAT), an enzyme of fatty acid beta-oxidation, are reported. The subunit, a typical thiolase, is a combination of two similar alpha/beta domains capped with a loop domain. The comparison of AtKAT with the Saccharomyces cerevisiae homologue (ScKAT) structure reveals a different placement of subunits within the functional dimers and that a polypeptide segment forming an extended loop around the open catalytic pocket of ScKAT converts to alpha-helix in AtKAT, and occludes the active site.

Structure of the manganese superoxide dismutase from Deinococcus radiodurans in two crystal forms.

The structure of the manganese superoxide dismutase (Mn-SOD; DR1279) from Deinococcus radiodurans has been determined in two different crystal forms. Both crystal forms are monoclinic with space group P2(1). Form I has unit-cell parameters a = 44.

Tryparedoxins from Crithidia fasciculata and Trypanosoma brucei: photoreduction of the redox disulfide using synchrotron radiation and evidence for a conformational switch implicated in function.

Tryparedoxin (TryX) is a member of the thioredoxin (TrX) fold family involved in the regulation of oxidative stress in parasitic trypanosomatids. Like TrX, TryX carries a characteristic Trp-Cys-Xaa-Xaa-Cys motif, which positions a redox-active disulfide underneath a tryptophan lid. We report the structure of a Crithidia fasciculata tryparedoxin isoform (CfTryX2) in two crystal forms and compare them with structures determined previously.

De novo phasing of two crystal forms of tryparedoxin II using the anomalous scattering from S atoms: a combination of small signal and medium resolution reveals this to be a general tool for solving protein crystal structures.

The de novo phasing of the structures of two crystal forms of tryparedoxin II from Crithidia fasciculata has been carried out using single-wavelength anomalous diffraction techniques exploiting only the small anomalous signal from the S atoms intrinsic to the native protein. Data were collected at 1.77 A wavelength, where the Bijvoet ratio is approximately 1.