title: Crystallization of the bifunctional biotin operon repressor.
abstract: The bifunctional birA gene product, BirA, which represses the biotin biosynthetic bio operon and also activates biotin in Escherichia coli, has been crystallized. The crystals have the tetragonal space group P4(1)2(1)2, or its enantiomorph, with unit cell dimensions a = b = 114.0 A and c = 60.2 A and diffract to at least 2.3 A resolution. The crystal packing requires that the monomers of the birA protein be arranged as dimers with two-fold symmetry. BirA is the first protein to be crystallized that is both a transcriptional regulator and an enzyme.
authors.affiliation: Institute of Molecular Biology, University of Oregon, Eugene 97403.
authors.forename: R G
authors.initials: RG
authors.lastname: Brennan
authors.forename: S
authors.initials: S
authors.lastname: Vasu
authors.forename: B W
authors.initials: BW
authors.lastname: Matthews
authors.forename: A J
authors.initials: AJ
authors.lastname: Otsuka
mesh_terms: D001426:Bacterial Proteins / Q000302:isolation & purification; D001710:Biotin / Q000096:biosynthesis*; D019731:Carbon-Nitrogen Ligases; D003460:Crystallization; D004926:Escherichia coli / Q000235:genetics; D029968:Escherichia coli Proteins; D046911:Macromolecular Substances; D009876:Operon; D011487:Protein Conformation; D012097:Repressor Proteins / Q000302:isolation & purification; D014157:Transcription Factors / Q000302:isolation & purification
chemical_list: D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D046911:Macromolecular Substances; D012097:Repressor Proteins; D014157:Transcription Factors; D001710:Biotin; D019731:Carbon-Nitrogen Ligases; C058125:birA protein, E coli