Preparation, crystallization and preliminary X-ray analysis of XC2382, an ApaG protein of unknown structure from Xanthomonas campestris

Xanthomonas campestris pv. campestris is the causative agent of black rot, one of the major worldwide diseases of cruciferous crops. Its genome encodes approximately 4500 proteins, roughly one third of which have unknown function. XC2382 is one such protein, with a MW of 14.2 kDa. Based on a bioinformatics study, it was annotated as an ApaG gene product that serves multiple functions. The ApaG protein has been overexpressed in Escherichia coli, purified and crystallized using the hanging-drop vapour-diffusion method. The crystals diffracted to a resolution of at least 2.30 Å. They are tetragonal and belong to space group P4_1/3, with unit-cell parameters a = b = 57.6, c = 122.9 Å. There are two, three or four molecules in the asymmetric unit.