Expression, purification, crystallization and preliminary X-ray analysis of a DNA-binding protein from Methanococcus jannaschii

A small DNA-binding protein of 87 amino-acid residues from the hyperthermophilic archaeon Methanococcus jannaschii (Mja10b) was cloned and overexpressed in Escherichia coli. The protein was crystallized and the crystals belong to the space group P6₁22/P6₅22, with unit-cell parameters a = b = 50.85, c = 124.02 Å, α = β = 90, γ = 120°. The crystals diffracted to a maximum resolution of 2.2 Å at 100 K using Cu Kα radiation. The presence of one molecule per asymmetric unit gives a crystal volume per protein mass (V_M) of 2.4 ų Da⁻¹ and a solvent content of 49% by volume. A full set of X-­ray diffraction data was collected to 2.2 Å from the native crystal.