title: Structure of the RNA-directed RNA polymerase from the cystovirus φ12.
abstract: We have determined the structure of P2, the self-priming RdRp from cystovirus φ12 in two crystal forms (A, B) at resolutions of 1.7 Å and 2.1 Å. Form A contains Mg(2+) bound at a site that deviates from the canonical noncatalytic position seen in form B. These structures provide insight into the temperature sensitivity of a ts-mutant. However, the tunnel through which template ssRNA accesses the active site is partially occluded by a flexible loop; this feature, along with suboptimal positioning of other structural elements that prevent the formation of a stable initiation complex, indicate an inactive conformation in crystallo.
authors.affiliation: Department of Chemistry, The City College of New York, New York, New York 10031, USA.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Ren
authors.forename: Matthew
authors.initials: M
authors.lastname: C Franklin
authors.forename: Ranajeet
authors.initials: R
authors.lastname: Ghose
mesh_terms: D001665:Binding Sites; D020134:Catalytic Domain; D018360:Crystallography, X-Ray; D017910:Cystoviridae / Q000737:chemistry / Q000201:enzymology* / Q000378:metabolism; D008274:Magnesium / Q000378:metabolism; D008968:Molecular Conformation; D012313:RNA / Q000378:metabolism; D012324:RNA-Dependent RNA Polymerase / Q000737:chemistry* / Q000378:metabolism
chemical_list: D012313:RNA; D012324:RNA-Dependent RNA Polymerase; D008274:Magnesium
keywords: RNA-directed RNA polymerase; bacteriophage; cystovirus; de novo initiation; replication; transcription