Crystallization and preliminary X-ray analysis of ferric enterobactin receptor FepA, an integral membrane protein from Escherichia coli.

Diffraction-quality crystals have been obtained of the integral membrane protein ferric enterobactin receptor (FepA) from the outer membrane of Escherichia coli. Crystals were grown using the zwitterionic detergent lauryldimethylamine oxide (LDAO), the precipitants polyethylene glycol (PEG) 1000 and sodium chloride, and the additive heptane-1,2,3-triol; they have the symmetry of the orthorhomic space group C2221 with a = 112.2, b = 137.2 and c = 135. 4 A and diffract to 2.5 A resolution. The crystals were flash-cooled and a preliminary data set was collected at 103 K. The crystals are suitable for three-dimensional structure analysis.