title: Visualization of membrane protein domains by cryo-electron microscopy of dengue virus.
abstract: Improved technology for reconstructing cryo-electron microscopy (cryo-EM) images has now made it possible to determine secondary structural features of membrane proteins in enveloped viruses. The structure of mature dengue virus particles was determined to a resolution of 9.5 A by cryo-EM and image reconstruction techniques, establishing the secondary structural disposition of the 180 envelope (E) and 180 membrane (M) proteins in the lipid envelope. The alpha-helical 'stem' regions of the E molecules, as well as part of the N-terminal section of the M proteins, are buried in the outer leaflet of the viral membrane. The 'anchor' regions of E and the M proteins each form antiparallel E-E and M-M transmembrane alpha-helices, leaving their C termini on the exterior of the viral membrane, consistent with the predicted topology of the unprocessed polyprotein. This is one of only a few determinations of the disposition of transmembrane proteins in situ and shows that the nucleocapsid core and envelope proteins do not have a direct interaction in the mature virus.
authors.affiliation: Department of Biological Sciences, Lilly Hall, 915 W. State Street, Purdue University, West Lafayette, Indiana 47907, USA.
authors.forename: Wei
authors.initials: W
authors.lastname: Zhang
authors.forename: Paul R
authors.initials: PR
authors.lastname: Chipman
authors.forename: Jeroen
authors.initials: J
authors.lastname: Corver
authors.forename: Peter R
authors.initials: PR
authors.lastname: Johnson
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhang
authors.forename: Suchetana
authors.initials: S
authors.lastname: Mukhopadhyay
authors.forename: Timothy S
authors.initials: TS
authors.lastname: Baker
authors.forename: James H
authors.initials: JH
authors.lastname: Strauss
authors.forename: Michael G
authors.initials: MG
authors.lastname: Rossmann
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Kuhn
mesh_terms: D020285:Cryoelectron Microscopy; D003716:Dengue Virus / Q000378:metabolism / Q000648:ultrastructure*; D019251:Nucleocapsid / Q000378:metabolism; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D014763:Viral Matrix Proteins / Q000378:metabolism / Q000648:ultrastructure*
chemical_list: D014763:Viral Matrix Proteins