Crystallization and preliminary X-ray crystallographic studies on the bacteriophage Φ6 RNA-dependent RNA polymerase

The RNA-dependent RNA polymerase (P2) from bacteriophage Φ6 has been cloned and the protein overexpressed in Escherichia coli to produce an active enzyme. A fully substituted selenomethionyl version of the protein has also been produced. Crystals of both proteins have been grown; most belong to the monoclinic space group P2₁, with unit-cell parameters a = 105.9, b = 94.0, c = 140.9 Å, β = 101.4°, but some are trigonal (space group P3₁ or P3₂), with unit-cell parameters a = b = 110.1, c = 159.4 Å, γ = 120°. Both crystal forms occur in the same crystallization drop and are morphologically indistinguishable. Native data sets have been collected from both types of crystals to better than 3 Å resolution.