Crystallization and preliminary X-ray diffraction analysis of Salmonella typhi PilS

The structure determination of PilS, a type IV pilin, by X-ray crystallography is reported. The recombinant protein from Salmonella typhi was overexpressed, purified and crystallized. The crystals belong to space group P2₁2₁2, with unit-cell parameters a = 77.88, b = 114.53, c = 31.75 Å. The selenomethionine derivative of the PilS protein was overexpressed, purified and crystallized in the same space group. Data sets have been collected to 2.1 Å resolution from the selenomethionine-derivative crystal using synchrotron radiation for multiwavelength anomalous dispersion (MAD) phasing.