Human DJ-1 and Escherichia coli Hsp31 belong to ThiJ/PfpI family, whose members contain a conserved domain. DJ-1 is associated with autosomal recessive early onset parkinsonism and Hsp31 is a molecular chaperone. Structural comparisons between DJ-1, Hsp31, and an Archaea protease, a member of ThiJ/PfpI family, lead to the identification of the chaperone activity of DJ-1 and the proteolytic activity of Hsp31. Moreover, the comparisons provide insights into how the functional diversity is realized in proteins that share an evolutionarily conserved domain. On the basis of the chaperone activity the possible role of DJ-1 in the pathogenesis of Parkinson's disease is discussed.

No abstract

Background: Pediocin-like bacteriocins, ribosomally-synthesized antimicrobial peptides, are generally coexpressed with cognate immunity proteins in order to protect the bacteriocinproducer from its own bacteriocin. As a step for understanding the mode of action of immunity proteins, we determined the crystal structure of PedB, a pediocin-like immunity protein conferring immunity to pediocin PP-1.

A yedU gene product with a molecular mass of 31 kDa is a hypothetical protein with no known function. The protein was puri®ed and crystallized at 296 K. X-ray diffraction data have been collected to 2.3 A Ê using synchrotron radiation. The crystals belong to the primitive orthorhombic system, with unit-cell parameters a = 50.56, b = 63.45, c = 168.02 A Ê . The asymmetric unit contains two monomers of the protein, with a corresponding V M of 2.25 A Ê 3 Da À1 and a solvent content of 44.84%.

The N-terminal DNA-binding domain of BldD from Streptomyces coelicolor A3(2) was crystallized by the hanging-drop vapour-diffusion method at 296 K. A 1.8 angstroms data set has been collected using synchrotron radiation at Pohang Light Source, South Korea. The crystal belongs to the monoclinic space group C2, with unit-cell parameters a = 77.2, b = 31.8, c = 33.6 angstroms, beta = 105.1 degrees. Analysis of the packing density shows that the asymmetric unit probably contains one molecule, with a solvent content of 43.6%.