title: DNA mobility in crystals of a nonspecific lambda cro/DNA complex.
abstract: DNA location in the crystal of the nonspecific lambda cro/(GT)4.(AC)4 complex has been studied by the isomorphous replacement method using iodinated and brominated oligonucleotides. The results of the search for heavy atom positions combined with previously obtained molecular replacement data suggest that the DNA octamer occupies two overlapping positions, each of the two duplexes (GTGTGTGT).(ACACACAC) belonging to the same imaginary longer double helix and differing only in the shift by two base pairs along the common sugar-phosphate backbone. In the crystals of the heavy atom derivatives different orientations of the DNA octamer are observed as well. It seems reasonable that the DNA mobility of both kinds might be a common feature of crystals of nonspecific repressor/DNA complexes.
authors.affiliation: Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow.
authors.forename: D E
authors.initials: DE
authors.lastname: Klimenko
authors.forename: B K
authors.initials: BK
authors.lastname: Chernov
authors.forename: L V
authors.initials: LV
authors.lastname: Malinina
mesh_terms: D001483:Base Sequence; D018360:Crystallography, X-Ray; D004247:DNA / Q000737:chemistry* / Q000378:metabolism; D004268:DNA-Binding Proteins; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D012097:Repressor Proteins / Q000737:chemistry* / Q000378:metabolism; D014764:Viral Proteins; D054334:Viral Regulatory and Accessory Proteins
chemical_list: D004268:DNA-Binding Proteins; D012097:Repressor Proteins; D014764:Viral Proteins; D054334:Viral Regulatory and Accessory Proteins; C016649:phage repressor proteins; D004247:DNA