title: Crystallization and preliminary crystallographic analysis of an Enterococcus faecalis repressor protein, CylR2, involved in regulating cytolysin production through quorum-sensing.
abstract: CylR2 is one of two regulatory proteins associated with the quorum-sensing-dependent synthesis of cytolysin in the common pathogen Enterococcus faecalis. The protein was expressed with a C-terminal six-histidine tag and purified to homogeneity with a cobalt-affinity column followed by size-exclusion chromatography. Both native and SeMet proteins were produced and crystallized. Complete X-ray diffraction data sets were collected from a native crystal, which diffracted to 2.3 angstroms resolution, and a SeMet crystal, which diffracted to 2.1 angstroms. The crystals were tetragonal, belonging to space group P4(1) or P4(3), with unit-cell parameters a = b = 66.2, c = 40.9 angstroms, alpha = beta = gamma = 90 degrees. Based on the calculated Matthews coefficient of 2.6 angstroms3 Da(-1) as well as analysis of anomalous difference Patterson maps, the asymmetric unit most likely contains two molecules of CylR2.
authors.affiliation: Fundamental Sciences, Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA 99352, USA.
authors.forename: Shuisong
authors.initials: S
authors.lastname: Ni
authors.forename: Kathleen
authors.initials: K
authors.lastname: McAteer
authors.forename: Dirksen E
authors.initials: DE
authors.lastname: Bussiere
authors.forename: Michael A
authors.initials: MA
authors.lastname: Kennedy
mesh_terms: D003001:Cloning, Molecular; D003460:Crystallization; D018360:Crystallography, X-Ray / Q000379:methods*; D004268:DNA-Binding Proteins / Q000737:chemistry*; D004591:Electrophoresis, Polyacrylamide Gel; D013293:Enterococcus faecalis / Q000378:metabolism*; D006639:Histidine / Q000737:chemistry; D008562:Membrane Glycoproteins / Q000737:chemistry*; D054353:Perforin; D052899:Pore Forming Cytotoxic Proteins; D017434:Protein Structure, Tertiary; D012097:Repressor Proteins / Q000737:chemistry*; D014158:Transcription, Genetic; D014961:X-Ray Diffraction
chemical_list: D004268:DNA-Binding Proteins; D008562:Membrane Glycoproteins; D052899:Pore Forming Cytotoxic Proteins; D012097:Repressor Proteins; D054353:Perforin; D006639:Histidine