title: The Ebola Virus VP30-NP Interaction Is a Regulator of Viral RNA Synthesis.
abstract: Filoviruses are capable of causing deadly hemorrhagic fevers. All nonsegmented negative-sense RNA-virus nucleocapsids are composed of a nucleoprotein (NP), a phosphoprotein (VP35) and a polymerase (L). However, the VP30 RNA-synthesis co-factor is unique to the filoviruses. The assembly, structure, and function of the filovirus RNA replication complex remain unclear. Here, we have characterized the interactions of Ebola, Sudan and Marburg virus VP30 with NP using in vitro biochemistry, structural biology and cell-based mini-replicon assays. We have found that the VP30 C-terminal domain interacts with a short peptide in the C-terminal region of NP. Further, we have solved crystal structures of the VP30-NP complex for both Ebola and Marburg viruses. These structures reveal that a conserved, proline-rich NP peptide binds a shallow hydrophobic cleft on the VP30 C-terminal domain. Structure-guided Ebola virus VP30 mutants have altered affinities for the NP peptide. Correlation of these VP30-NP affinities with the activity for each of these mutants in a cell-based mini-replicon assay suggests that the VP30-NP interaction plays both essential and inhibitory roles in Ebola virus RNA synthesis.
authors.affiliation: Department of Immunology and Microbial Sciences, The Scripps Research Institute, La Jolla, California, United States of America.
authors.forename: Robert N
authors.initials: RN
authors.lastname: Kirchdoerfer
authors.affiliation: Department of Immunology and Microbial Sciences, The Scripps Research Institute, La Jolla, California, United States of America.
authors.forename: Crystal L
authors.initials: CL
authors.lastname: Moyer
authors.affiliation: Department of Immunology and Microbial Sciences, The Scripps Research Institute, La Jolla, California, United States of America.
authors.forename: Dafna M
authors.initials: DM
authors.lastname: Abelson
authors.affiliation: Department of Immunology and Microbial Sciences, The Scripps Research Institute, La Jolla, California, United States of America.|Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, California, United States of America.
authors.forename: Erica Ollmann
authors.initials: EO
authors.lastname: Saphire
mesh_terms: D015153:Blotting, Western; D029043:Ebolavirus / Q000737:chemistry / Q000235:genetics*; D005455:Fluorescent Antibody Technique; D047468:Immunoprecipitation; D009698:Nucleoproteins / Q000737:chemistry* / Q000235:genetics*; D012367:RNA, Viral / Q000096:biosynthesis*; D060888:Real-Time Polymerase Chain Reaction; D014157:Transcription Factors / Q000737:chemistry* / Q000235:genetics*; D014158:Transcription, Genetic / Q000502:physiology; D014764:Viral Proteins / Q000737:chemistry* / Q000235:genetics*; D014779:Virus Replication / Q000502:physiology
chemical_list: D009698:Nucleoproteins; D012367:RNA, Viral; D014157:Transcription Factors; C479897:VP30 protein, ebola virus; D014764:Viral Proteins