Noncatalytic ions direct the RNA-dependent RNA polymerase of bacterial double-stranded RNA virus ϕ6 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 (University of Helsinki) , Dennis H. Bamford (University of Helsinki) , David I. Stuart (Wellcome Trust Centre for Human Genetics, University of Oxford; Diamond Light Source) , Jonathan M. Grimes (Wellcome Trust Centre for Human Genetics, University of Oxford; Diamond Light Source)
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

Diamond Keywords: Viruses

Subject Areas: Biology and Bio-materials, Chemistry


Instruments: I03-Macromolecular Crystallography

Other Facilities: ID14-EH2 at ESRF

Added On: 04/04/2012 12:08

Discipline Tags:

Pathogens Health & Wellbeing Biochemistry Chemistry Structural biology Biophysics Life Sciences & Biotech

Technical Tags:

Diffraction Macromolecular Crystallography (MX)