title: Characterization of the banana streak virus capsid protein and mapping of the immunodominant continuous B-cell epitopes to the surface-exposed N terminus.
abstract: This study identified the structural proteins of two badnavirus species, Banana streak MY virus (BSMYV) and Banana streak OL virus (BSOLV), and mapped the distribution of continuous B-cell epitopes. Two different capsid protein (CP) isoforms of about 44 and 40 kDa (CP1 and CP2) and the virion-associated protein (VAP) were consistently associated with purified virions. For both viral species, the N terminus of CP2 was successfully sequenced by Edman degradation but that of CP1 was chemically blocked. De novo peptide sequencing of tryptic digests suggested that CP1 and CP2 derive from the same region of the P3 polyprotein but differ in the length of either the N or the C terminus. A three-dimensional model of the BSMYV-CP was constructed, which showed that the CP is a multi-domain structure, containing homologues of the retroviral capsid and nucleocapsid proteins, as well as a third, intrinsically disordered protein region at the N terminus, henceforth called the NID domain. Using the Pepscan approach, the immunodominant continuous epitopes were mapped to the NID domain for five different species of banana streak virus. Anti-peptide antibodies raised against these epitopes in BSMYV were successfully used for detection of native virions and denatured CPs in serological assays. Immunoelectron microscopy analysis of the virion surface using the anti-peptide antibodies confirmed that the NID domain is exposed on the surface of virions, and that the difference in mass of the two CP isoforms is due to variation in length of the NID domain.
authors.affiliation: Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, GPO Box 267, Brisbane, Queensland 4001, Australia.|School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, Queensland 4072, Australia.|Plant Biosecurity Cooperative Research Centre, LPO Box 5012, Bruce, Australian Capital Territory 2617, Australia.
authors.forename: Jenny N
authors.initials: JN
authors.lastname: Vo
authors.affiliation: Plant Biosecurity Cooperative Research Centre, LPO Box 5012, Bruce, Australian Capital Territory 2617, Australia.|Queensland Department of Agriculture, Fisheries and Forestry, GPO Box 267, Brisbane, Queensland 4001, Australia.
authors.forename: Paul R
authors.initials: PR
authors.lastname: Campbell
authors.affiliation: School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, Queensland 4072, Australia.
authors.forename: Nur N
authors.initials: NN
authors.lastname: Mahfuz
authors.affiliation: School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, Queensland 4072, Australia.
authors.forename: Ras
authors.initials: R
authors.lastname: Ramli
authors.affiliation: CSIRO Mathematics, Informatics and Statistics, Ecosciences Precinct, 41 Boggo Road, Dutton Park, Queensland 4102, Australia.
authors.forename: Daniel
authors.initials: D
authors.lastname: Pagendam
authors.affiliation: School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, Queensland 4072, Australia.
authors.forename: Ross
authors.initials: R
authors.lastname: Barnard
authors.affiliation: Plant Biosecurity Cooperative Research Centre, LPO Box 5012, Bruce, Australian Capital Territory 2617, Australia.|Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, GPO Box 267, Brisbane, Queensland 4001, Australia.
authors.forename: Andrew D W
authors.initials: ADW
authors.lastname: Geering
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000818:Animals; D019195:Badnavirus / Q000737:chemistry / Q000235:genetics / Q000276:immunology*; D036022:Capsid Proteins / Q000737:chemistry* / Q000235:genetics / Q000276:immunology*; D018604:Epitope Mapping; D018985:Epitopes, B-Lymphocyte / Q000737:chemistry* / Q000235:genetics / Q000276:immunology*; D008969:Molecular Sequence Data; D028521:Musa / Q000821:virology*; D010935:Plant Diseases / Q000276:immunology / Q000821:virology*; D016415:Sequence Alignment
chemical_list: D036022:Capsid Proteins; D018985:Epitopes, B-Lymphocyte