title: Crystal structure of the homo-tetrameric DNA binding domain of Escherichia coli single-stranded DNA-binding protein determined by multiwavelength x-ray diffraction on the selenomethionyl protein at 2.9-A resolution.
abstract: The crystal structure of the tetrameric DNA-binding domain of the single-stranded DNA binding protein from Escherichia coli was determined at a resolution of 2.9 A using multiwavelength anomalous dispersion. Each monomer in the tetramer is topologically similar to an oligomer-binding fold. Two monomers each contribute three beta-strands to a single six-stranded beta-sheet to form a dimer. Two dimer-dimer interfaces are observed within the crystal. One of these stabilizes the tetramer in solution. The other interface promotes a superhelical structure within the crystal that may reflect tetramer-tetramer interactions involved in the positive cooperative binding of the single-stranded DNA-binding protein to single-stranded DNA.
authors.affiliation: Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO 63110, USA.
authors.forename: S
authors.initials: S
authors.lastname: Raghunathan
authors.forename: C S
authors.initials: CS
authors.lastname: Ricard
authors.forename: T M
authors.initials: TM
authors.lastname: Lohman
authors.forename: G
authors.initials: G
authors.lastname: Waksman
mesh_terms: D000595:Amino Acid Sequence; D001665:Binding Sites; D018360:Crystallography, X-Ray; D004277:DNA, Single-Stranded / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000737:chemistry* / Q000378:metabolism; D004926:Escherichia coli / Q000737:chemistry*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011487:Protein Conformation
chemical_list: D004277:DNA, Single-Stranded; D004268:DNA-Binding Proteins