title: Structure of the effector-binding domain of deoxyribonucleoside regulator DeoR from Bacillus subtilis.
abstract: Deoxyribonucleoside regulator (DeoR) from Bacillus subtilis negatively regulates expression of enzymes involved in the catabolism of deoxyribonucleosides and deoxyribose. The DeoR protein is homologous to the sorbitol operon regulator family of metabolic regulators and comprises an N-terminal DNA-binding domain and a C-terminal effector-binding domain. We have determined the crystal structure of the effector-binding domain of DeoR (C-DeoR) in free form and in covalent complex with its effector deoxyribose-5-phosphate (dR5P). This is the first case of a covalently attached effector molecule captured in the structure of a bacterial transcriptional regulator. The dR5P molecule is attached through a Schiff base linkage to residue Lys141. The crucial role of Lys141 in effector binding was confirmed by mutational analysis and mass spectrometry of Schiff base adducts formed in solution. Structural analyses of the free and effector-bound C-DeoR structures provided a structural explanation for the mechanism of DeoR function as a molecular switch.
  
  
  METHODS
  Atomic coordinates and structure factors for crystal structures of free C-DeoR and the covalent Schiff base complex of C-DeoR with dR5P have been deposited in the Protein Data Bank with accession codes 4OQQ and 4OQP, respectively.
  C-DeoR and C-DeoR bind by x-ray crystallography (View interaction) DeoR and DeoR bind by molecular sieving (1, 2).
authors.affiliation: Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Prague, Czech Republic; Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, Prague, Czech Republic.
authors.forename: Jana
authors.initials: J
authors.lastname: Škerlová
authors.forename: Milan
authors.initials: M
authors.lastname: Fábry
authors.forename: Martin
authors.initials: M
authors.lastname: Hubálek
authors.forename: Zbyszek
authors.initials: Z
authors.lastname: Otwinowski
authors.forename: Pavlína
authors.initials: P
authors.lastname: Rezáčová
mesh_terms: D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D001412:Bacillus subtilis; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics; D001665:Binding Sites; D018360:Crystallography, X-Ray; D006860:Hydrogen Bonding; D008958:Models, Molecular; D016297:Mutagenesis, Site-Directed; D011485:Protein Binding; D055503:Protein Multimerization; D020836:Protein Structure, Quaternary; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D012097:Repressor Proteins / Q000737:chemistry* / Q000235:genetics; D012545:Schiff Bases / Q000737:chemistry; D012996:Solutions; D040681:Structural Homology, Protein
chemical_list: D001426:Bacterial Proteins; D012097:Repressor Proteins; D012545:Schiff Bases; D012996:Solutions
keywords: Schiff base; X-ray crystallography; dimeric interface; effector binding; transcription repressor