Purification and crystallization of Escherichia coli pseudouridine synthase RluD

RluD is the pseudouridine (ψ) synthase responsible for forming ψ1911, ψ1915 and ψ1917 in Escherichia coli 23S RNA. Out of the 11 ψ synthases in E. coli, only cells lacking RluD show a severe growth defect. In addition, RluD belongs to the RluA family of ψ synthases, one of the two remaining families without a representative crystal structure. In this paper, the crystallization of selenomethionine-substituted RluD by the hanging-drop method is reported. The crystals diffract to 1.9 Å and belong to space group P4₃2₁2, with unit-cell parameters a = b = 75.14, c = 181.81 Å. Synchrotron radiation was used on a single crystal to collect a complete multiwavelength anomalous dispersion (MAD) data set to 2.0 Å resolution.