Open AccessCrystallization and preliminary X‐ray analysis of BigR, a transcription repressor from Xylella fastidiosa involved in biofilm formation
Author(s) -
Barbosa Rosicler Lázaro,
Rinaldi Fábio Cupri,
Guimarães Beatriz Gomes,
Benedetti Celso Eduardo
Publication year - 2007
Publication title -
acta crystallographica section f
Language(s) - English
Resource type - Journals
ISSN - 1744-3091
DOI - 10.1107/s1744309107028722
Subject(s) - operon , repressor , transcription (linguistics) , biofilm , xylella fastidiosa , biology , agrobacterium tumefaciens , chemistry , crystallography , microbiology and biotechnology , transcription factor , genetics , bacteria , transformation (genetics) , gene , escherichia coli , linguistics , philosophy
BigR ( bi ofilm g rowth‐associated r epressor) is a novel repressor protein that regulates the transcription of an operon implicated in biofilm growth in both Xylella fastidiosa and Agrobacterium tumefaciens . This protein binds to a palindromic TA‐rich element located in the promoter of the BigR operon and strongly represses transcription of the operon. BigR contains a helix–turn–helix (HTH) domain that is found in some members of the ArsR/SmtB family of metal sensors, which control metal resistance in bacteria. Although functional studies have suggested that BigR does not act as a metal sensor, the presence of two cysteines and a methionine in its primary structure raised the possibility of BigR being a metal‐ligand protein. In order to gain new insights into the protein structure and its possible interaction with a metal ion or effector ligand, BigR from X. fastidiosa was crystallized in native and selenomethionine (SeMet) labelled forms using the hanging‐drop vapour‐diffusion method. X‐ray diffraction data were collected from native and SeMet crystals to resolutions of 1.95 and 2.2 Å, respectively. Both crystals belong to space group P 321 and contain one molecule per asymmetric unit.