title: Crystallization and preliminary crystallographic analysis of T7 RNA polymerase elongation complex.
abstract: Stable transcription-elongation complexes consisting of T7 RNA polymerase (molecular mass 99 kDa) in association with a nucleic acid scaffold consisting of an 8 bp RNA-DNA hybrid and 10 bp of downstream DNA were assembled and crystallized by the sitting-drop vapour-diffusion technique under near-physiological conditions. The crystals diffract beyond 2.6 A resolution and belong to space group P1, with unit-cell parameters a = 79.91, b = 84.97, c = 202 A, alpha = 90.36, beta = 92.97, gamma = 109.94 degrees. An unambiguous molecular-replacement solution was found using the C-terminal portion of the T7 RNA polymerase structure from the early initiation complex as a search model. Model building and structure refinement are now in progress.
authors.affiliation: Morse Institute of Molecular Genetics, Department of Microbiology and Immunology, SUNY Health Science Center at Brooklyn, 450 Clarkson Avenue, Brooklyn, New York 11203-2098, USA.
authors.forename: Dmitry
authors.initials: D
authors.lastname: Temiakov
authors.forename: Tahir H
authors.initials: TH
authors.lastname: Tahirov
authors.forename: Michael
authors.initials: M
authors.lastname: Anikin
authors.forename: William T
authors.initials: WT
authors.lastname: McAllister
authors.forename: Dmitry G
authors.initials: DG
authors.lastname: Vassylyev
authors.forename: Shigeyuki
authors.initials: S
authors.lastname: Yokoyama
mesh_terms: D017123:Bacteriophage T7 / Q000201:enzymology*; D020029:Base Pairing; D001483:Base Sequence; D001665:Binding Sites; D003460:Crystallization; D018360:Crystallography, X-Ray; D004247:DNA / Q000235:genetics / Q000378:metabolism; D012321:DNA-Directed RNA Polymerases / Q000737:chemistry* / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D008958:Models, Molecular; D011485:Protein Binding; D012313:RNA / Q000235:genetics / Q000378:metabolism; D014158:Transcription, Genetic
chemical_list: D012313:RNA; D004247:DNA; D012321:DNA-Directed RNA Polymerases