title: Dimerization of recombinant tobacco mosaic virus movement protein.
abstract: The p30 movement protein (MP) is essential for cell-to-cell spread of tobacco mosaic virus in planta. We used anion-exchange chromatography and preparative sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) to obtain highly purified 30-kDa MP, which migrated as a single band in native PAGE. Analytical ultracentrifugation suggested that the protein was monodisperse and dimeric in the nonionic detergent n-octyl-beta-D-glucopyranoside. Circular dichroism (CD) spectroscopy showed that the detergent-solubilized protein contained significant alpha-helical secondary structure. Proteolysis of the C-tail generated a trypsin-resistant core that was a mixture of primarily monomers and some dimers. We propose that MP dimers are stabilized by electrostatic interactions in the C terminus as well as hydrophobic interactions between putative transmembrane alpha-helical coiled coils.
authors.affiliation: Department of Cell Biology, The Scripps Research Institute, Scripps Clinic, La Jolla, California 92037, USA.
authors.forename: Laurence M
authors.initials: LM
authors.lastname: Brill
authors.forename: Songpon
authors.initials: S
authors.lastname: Dechongkit
authors.forename: Byron
authors.initials: B
authors.lastname: DeLaBarre
authors.forename: Jonathon
authors.initials: J
authors.lastname: Stroebel
authors.forename: Roger N
authors.initials: RN
authors.lastname: Beachy
authors.forename: Mark
authors.initials: M
authors.lastname: Yeager
mesh_terms: D000595:Amino Acid Sequence; D002942:Circular Dichroism; D019281:Dimerization; D008958:Models, Molecular; D008969:Molecular Sequence Data; D053830:Plant Viral Movement Proteins; D020836:Protein Structure, Quaternary; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D012995:Solubility; D014027:Tobacco Mosaic Virus / Q000737:chemistry*; D014357:Trypsin / Q000378:metabolism; D014461:Ultracentrifugation; D014764:Viral Proteins / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism*
chemical_list: D053830:Plant Viral Movement Proteins; D011994:Recombinant Proteins; D014764:Viral Proteins; D014357:Trypsin