Preparation, crystallization and preliminary X-ray characterization of a conserved hypothetical protein XC1692 from Xanthomonas campestris.

Xanthomonas campestris pv. campestris strain 17 is a Gram-negative yellow-pigmented pathogenic bacterium that causes black rot, one of the major worldwide diseases of cruciferous crops. Its genome contains approximately 4500 genes, one third of which have no known structure and/or function yet are highly conserved among several different bacterial genuses. One of these gene products is XC1692 protein, containing 141 amino acids. It was overexpressed in Escherichia coli, purified and crystallized in a variety of forms using the hanging-drop vapour-diffusion method. The crystals diffract to at least 1.45 A resolution. They are hexagonal and belong to space group P6(3), with unit-cell parameters a = b = 56.9, c = 71.0 A. They contain one molecule per asymmetric unit.