Crystallization and X-ray diffraction analyses of the outer membrane pyochelin receptor FptA from Pseudomonas aeruginosa.

FptA, the pyochelin outer membrane receptor from Pseudomonas aeruginosa, is a siderophore receptor involved in iron uptake when the bacterium grows under iron limitation. Two crystal forms of the FptA-pyochelin complex were obtained under different crystallization conditions. They belong to space groups P1 and P2(1)2(1)2(1) and data sets were collected for both crystal forms. The triclinic crystals diffract to 3.2 A resolution and the orthorhombic crystals show a 1.9 A resolution limit. A data set at the peak of the iron K edge was also collected at 3.1 A resolution.