recombinant chimeric protein formed by the EnvZ catalytic domain with the HAMP domain of the Archaeoglobus fulgidus Af1503 receptor, with or without the point mutation A291F, sitting drop vapor diffusion method, mixing of 400 nl of 2 and 20 mg/mlprotein, respectively, in 30 mM MOPS, pH 7.0 and 50 mM NaCl, for the wild-type construct and in a buffer containing 20 mM MOPS, pH 7.0 and 100 mM NaCl for the A291F mutant, with 400 nl of reservoir solution and equilibration against 0.05 mL reservoir solution, containing 0.1 M MMT buffer, pH 4.0, and 25% (w/v) PEG 1500 for the wild-type fusion and 0.2 M lithium acetate and 20% w/v PEG 3350 for the A291F variant, 22°C, X-ray diffraction tructure determination and analysis. The structure shows a putatively active conformation of the catalytic domain, molecular replacement |
Escherichia coli |