title: Yeast RNA polymerase II at 5 A resolution.
abstract: Appropriate treatment of X-ray diffraction from an unoriented 18-heavy atom cluster derivative of a yeast RNA polymerase II crystal gave significant phase information to 5 A resolution. The validity of the phases was shown by close similarity of a 6 A electron density map to a 16 A molecular envelope of the polymerase from electron crystallography. Comparison of the 6 A X-ray map with results of electron crystallography of a paused transcription elongation complex suggests functional roles for two mobile protein domains: the tip of a flexible arm forms a downstream DNA clamp; and a hinged domain may serve as an RNA clamp, enclosing the transcript from about 8-18 residues upstream of the 3'-end in a tunnel.
authors.affiliation: Department of Structural Biology, Stanford University School of Medicine, Fairchild Science Center, California 94305, USA.
authors.forename: J
authors.initials: J
authors.lastname: Fu
authors.forename: A L
authors.initials: AL
authors.lastname: Gnatt
authors.forename: D A
authors.initials: DA
authors.lastname: Bushnell
authors.forename: G J
authors.initials: GJ
authors.lastname: Jensen
authors.forename: N E
authors.initials: NE
authors.lastname: Thompson
authors.forename: R R
authors.initials: RR
authors.lastname: Burgess
authors.forename: P R
authors.initials: PR
authors.lastname: David
authors.forename: R D
authors.initials: RD
authors.lastname: Kornberg
mesh_terms: D018360:Crystallography, X-Ray; D004247:DNA / Q000378:metabolism; D008854:Microscopy, Electron; D008958:Models, Molecular; D009038:Motion; D011487:Protein Conformation; D012313:RNA / Q000378:metabolism; D012319:RNA Polymerase II / Q000737:chemistry*; D012441:Saccharomyces cerevisiae / Q000201:enzymology*; D017356:Synchrotrons
chemical_list: D012313:RNA; D004247:DNA; D012319:RNA Polymerase II