Crystallization and preliminary diffraction studies of NodL, a rhizobial O ‐acetyl‐transferase involved in the host‐specific nodulation of legume roots

The NodL specified O ‐acetyltransferase from the microbial symbiont Rhizobium leguminosarum has been over‐expressed in Escherichia coli and purified using affinity‐elution dye chromatography as the key step. The protein has been crystallized at 20 °C in 18% PEG 600, 0.1 M Tris/HCl buffer, pH 8.5, containing 1% dioxane, 0.25% octyl‐β‐glucoside, and 5 mM coenzyme A using the hanging drop vapor diffusion method. Ambient temperature X‐ray diffraction studies reveal the space group to be hexagonal (P6 3 22) with lattice constants a = b = 77.08 å, c = 160.6 å, and α = β = 90°, γ = 120°. Crystals that are flash‐frozen to 120 K diffract beyond 2.7 å.