Open AccessExpression, purification, crystallization and preliminary X‐ray analysis of the DNA‐binding domain of Rhodobacter capsulatus MopB
Author(s) -
Müller Alexandra,
Schlicker Christine,
Fehringer Maria,
Masepohl Bernd,
Hofmann Eckhard
Publication year - 2011
Publication title -
acta crystallographica section f
Language(s) - English
Resource type - Journals
ISSN - 1744-3091
DOI - 10.1107/s1744309110054710
Subject(s) - rhodobacter , crystallization , dna , domain (mathematical analysis) , chemistry , crystallography , biochemistry , gene , mutant , organic chemistry , mathematics , mathematical analysis
The LysR‐type regulator MopB represses transcription of several target genes (including the nitrogen‐fixation gene anfA ) in Rhodobacter capsulatus at high molybdenum concentrations. In this study, the isolated DNA‐binding domain of MopB (MopB HTH ) was overexpressed in Escherichia coli . Purified MopB HTH bound the anfA promoter as shown by DNA mobility‐shift assays, demonstrating the function of the isolated regulator domain. MopB HTH was crystallized using the sitting‐drop vapour‐diffusion method in the presence of 0.2 M lithium sulfate, 0.1 M phosphate/citrate pH 4.2, 20%( w / v ) PEG 1000 at 291 K. The crystal belonged to space group P 3 1 21 or P 3 2 21, with unit‐cell parameters a = b = 61.84, c = 139.64 Å, α = β = 90, γ = 120°, and diffracted to 3.3 Å resolution at a synchrotron source.