Crystallization and Preliminary X-ray Analysis of the Periplasmic Dipeptide Binding Protein from Escherichia coli

Abstract

The periplasmic dipeptide-binding protein from Escherichia coli has been purified, freed of bound endogenous ligands, and crystallized. Crystals of the protein in complex with added dipeptides have been subjected to X-ray analysis. The crystals grow as hexagonal bipyramids or eye-shaped disks which have the symmetry of space group P6 1. The unit cell dimensions are a = b = 183 Å, c = 212 Å, and the diffraction pattern extends to 3·2 Å resolution with a conventional X-ray source.