title: Crystal Structure and Proteomics Analysis of Empty Virus-like Particles of Cowpea Mosaic Virus.
abstract: Empty virus-like particles (eVLPs) of Cowpea mosaic virus (CPMV) are currently being utilized as reagents in various biomedical and nanotechnology applications. Here, we report the crystal structure of CPMV eVLPs determined using X-ray crystallography at 2.3 Å resolution and compare it with previously reported cryo-electron microscopy (cryo-EM) of eVLPs and virion crystal structures. Although the X-ray and cryo-EM structures of eVLPs are mostly similar, there exist significant differences at the C terminus of the small (S) subunit. The intact C terminus of the S subunit plays a critical role in enabling the efficient assembly of CPMV virions and eVLPs, but undergoes proteolysis after particle formation. In addition, we report the results of mass spectrometry-based proteomics analysis of coat protein subunits from CPMV eVLPs and virions that identify the C termini of S subunits undergo proteolytic cleavages at multiple sites instead of a single cleavage site as previously observed.
authors.affiliation: Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA.
authors.forename: Nhung T
authors.initials: NT
authors.lastname: Huynh
authors.affiliation: Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds LS2 9JT, UK.
authors.forename: Emma L
authors.initials: EL
authors.lastname: Hesketh
authors.affiliation: Department of Biological Chemistry, John Innes Centre, Norwich Research Park, Colney, Norwich NR4 7UH, UK.
authors.forename: Pooja
authors.initials: P
authors.lastname: Saxena
authors.affiliation: Department of Biological Chemistry, John Innes Centre, Norwich Research Park, Colney, Norwich NR4 7UH, UK.
authors.forename: Yulia
authors.initials: Y
authors.lastname: Meshcheriakova
authors.affiliation: Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA.
authors.forename: You-Chan
authors.initials: YC
authors.lastname: Ku
authors.affiliation: Scripps Center for Metabolics and Mass Spectrometry, The Scripps Research Institute, La Jolla, CA 92037, USA.
authors.forename: Linh T
authors.initials: LT
authors.lastname: Hoang
authors.affiliation: Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA.
authors.forename: John E
authors.initials: JE
authors.lastname: Johnson
authors.affiliation: Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds LS2 9JT, UK.
authors.forename: Neil A
authors.initials: NA
authors.lastname: Ranson
authors.affiliation: Department of Biological Chemistry, John Innes Centre, Norwich Research Park, Colney, Norwich NR4 7UH, UK.
authors.forename: George P
authors.initials: GP
authors.lastname: Lomonossoff
authors.affiliation: Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA. Electronic address: reddyv@scripps.edu.
authors.forename: Vijay S
authors.initials: VS
authors.lastname: Reddy
mesh_terms: D036022:Capsid Proteins / Q000737:chemistry* / Q000378:metabolism; D017798:Comovirus / Q000737:chemistry* / Q000378:metabolism; D020285:Cryoelectron Microscopy; D018360:Crystallography, X-Ray / Q000379:methods*; D013058:Mass Spectrometry; D008958:Models, Molecular; D017433:Protein Structure, Secondary; D059748:Proteolysis; D040901:Proteomics / Q000379:methods*; D014764:Viral Proteins / Q000737:chemistry / Q000378:metabolism; D014771:Virion / Q000737:chemistry / Q000378:metabolism
chemical_list: D036022:Capsid Proteins; D014764:Viral Proteins
keywords: CPMV; cowpea mosaic virus; eVLPs; mass spectrometry; proteomic; structure