title: Conformational flexibility of bacterial RNA polymerase.
abstract: The structure of Escherichia coli core RNA polymerase (RNAP) was determined by cryo-electron microscopy and image processing of helical crystals to a nominal resolution of 15 A. Because of the high sequence conservation between the core RNAP subunits, we were able to interpret the E. coli structure in relation to the high-resolution x-ray structure of Thermus aquaticus core RNAP. A very large conformational change of the T. aquaticus RNAP x-ray structure, corresponding to opening of the main DNA/RNA channel by nearly 25 A, was required to fit the E. coli map. This finding reveals, at least partially, the range of conformational flexibility of the RNAP, which is likely to have functional implications for the initiation of transcription, where the DNA template must be loaded into the channel.
authors.affiliation: Laboratory of Molecular Biophysics, The Rockefeller University, New York, NY 10021, USA. darst@rockefeller.edu
authors.forename: Seth A
authors.initials: SA
authors.lastname: Darst
authors.forename: Natacha
authors.initials: N
authors.lastname: Opalka
authors.forename: Pablo
authors.initials: P
authors.lastname: Chacon
authors.forename: Andrey
authors.initials: A
authors.lastname: Polyakov
authors.forename: Catherine
authors.initials: C
authors.lastname: Richter
authors.forename: Gongyi
authors.initials: G
authors.lastname: Zhang
authors.forename: Willy
authors.initials: W
authors.lastname: Wriggers
mesh_terms: D003460:Crystallization; D012321:DNA-Directed RNA Polymerases / Q000737:chemistry*; D004926:Escherichia coli / Q000201:enzymology*; D008854:Microscopy, Electron; D011487:Protein Conformation
chemical_list: D012321:DNA-Directed RNA Polymerases