Noncatalytic Ions Direct the RNA-Dependent RNA Polymerase of Bacterial Double-Stranded RNA Virus 6 from De Novo Initiation to Elongation.

DOI: 10.1128/JVI.05168-11
PMID: 22205747

Authors: Sam Wright (Wellcome Trust Centre for Human Genetics, University of Oxford, U.K.) , Minna M Poranen (Institute of Biotechnology and Department of Biosciences, Viikki Biocenter, University of Helsinki, Finland) , Dennis H Bamford (Institute of Biotechnology and Department of Biosciences, Viikki Biocenter, University of Helsinki, Finland) , Dave Stuart (Diamond Light Source) , Jonathan Grimes (Division of Structural Biology, University of Oxford)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Journal of Virology , VOL 86 (5) , PAGES 2837-2849

State: Published (Approved)
Published: March 2012
Diamond Proposal Number(s): 6387

Abstract: RNA-dependent RNA polymerases (RdRps) are key to the replication of RNA viruses. A common divalent cation binding site, distinct from the positions of catalytic ions, has been identified in many viral RdRps. We have applied biochemical, biophysical, and structural approaches to show how the RdRp from bacteriophage 6 uses the bound noncatalytic Mn(2+) to facilitate the displacement of the C-terminal domain during the transition from initiation to elongation. We find that this displacement releases the noncatalytic Mn(2+), which must be replaced for elongation to occur. By inserting a dysfunctional Mg(2+) at this site, we captured two nucleoside triphosphates within the active site in the absence of Watson-Crick base pairing with template and mapped movements of divalent cations during preinitiation. These structures refine the pathway from preinitiation through initiation to elongation for the RNA-dependent RNA polymerization reaction, explain the role of the noncatalytic divalent cation in 6 RdRp, and pinpoint the previously unresolved Mn(2+)-dependent step in replication.

Journal Keywords: Binding; Cations ; Divalent ; Manganese ; Protein; Tertiary ; RNA; RNA ; Viral ; Transcription ; Genetic ; Viral; Virus Replication

Subject Areas: Biology and Bio-materials


Instruments: I03-Macromolecular Crystallography

Other Facilities: ESRF

Added On: 04/04/2012 12:08

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