Crystallization and preliminary X-ray diffraction analysis of two extracytoplasmic solute receptors of the DctP family from Bordetella pertussis.

DctP6 and DctP7 are two Bordetella pertussis proteins which belong to the extracytoplasmic solute receptors (ESR) superfamily. ESRs are involved in the transport of substrates from the periplasm to the cytosol of Gram-negative bacteria. DctP6 and DctP7 have been crystallized and diffraction data were collected using a synchrotron-radiation source. DctP6 crystallized in space group P4(1)2(1)2, with unit-cell parameters a = 108.39, b = 108.39, c = 63.09 A, while selenomethionyl-derivatized DctP7 crystallized in space group P2(1)2(1)2(1), with unit-cell parameters a = 64.87, b = 149.83, c = 170.65 A. The three-dimensional structure of DctP7 will be determined by single-wavelength anomalous diffraction, while the DctP6 structure will be solved by molecular-replacement methods.