Crystallization and preliminary X-ray analysis of the Escherichia coli UDP-MurNAc-tripeptide d-alanyl-d-alanine-adding enzyme (MurF)

Crystals of the Escherichia coli UDP‐MurNAc‐tripeptide d‐Ala‐d‐Ala‐adding protein (MurF), which catalyzes the formation of the last metabolite of the bacterial cell‐wall building block, have been grown in hanging‐drop vapor‐diffusion trials using PEG 8K as a precipitating agent. The crystals belong to hexagonal space group P61 or P65, with unit‐cell dimensions a = b = 74, c = 425 Å. The asymmetric unit contains two molecules, with a crystal volume per protein mass (Vm) of 3.4 Å3 Da−1 and a solvent content of about 64% by volume. A native data set to 2.8 Å resolution has been obtained from a frozen crystal using a synchrotron X‐ray source.