title: On the structures of filamentous bacteriophage Ff (fd, f1, M13).
abstract: The filamentous bacteriophage (Inovirus) strain Ff (fd, f1, M13) is widely used in molecular biophysics as a simple model system. A low resolution molecular model of the fd protein coat has been reported, derived from iterative helical real space reconstruction of cryo-electron micrographs (cryoEM). This model is significantly different from the model previously derived from X-ray fibre diffraction and solid-state NMR. We show that the cryoEM model agrees neither with solid-state NMR data nor with X-ray fibre diffraction data of fd, and has some puzzling structural features, for instance nanometre holes through the protein coat. We refine the cryoEM model against the X-ray data, and find that the model after refinement closely approximates the model derived directly from X-ray fibre diffraction and solid-state NMR data. We suggest possible reasons for the differences between the models derived from cryoEM and X-ray diffraction.
authors.affiliation: Department of Chemistry, University of British Columbia, Vancouver, BC, Canada.
authors.forename: S K
authors.initials: SK
authors.lastname: Straus
authors.forename: W R P
authors.initials: WR
authors.lastname: Scott
authors.forename: M F
authors.initials: MF
authors.lastname: Symmons
authors.forename: D A
authors.initials: DA
authors.lastname: Marvin
mesh_terms: D017104:Bacteriophage M13 / Q000737:chemistry / Q000378:metabolism*; D001703:Biophysics / Q000379:methods*; D002213:Capsid; D020285:Cryoelectron Microscopy / Q000379:methods*; D017912:Inovirus / Q000737:chemistry / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy; D008954:Models, Biological; D008958:Models, Molecular; D053758:Nanoparticles / Q000737:chemistry; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D014764:Viral Proteins / Q000737:chemistry; D014961:X-Ray Diffraction
chemical_list: D014764:Viral Proteins