title: Tale of two spikes in bacteriophage PRD1.
abstract: Structural comparisons between bacteriophage PRD1 and adenovirus have revealed an evolutionary relationship that has contributed significantly to current ideas on virus phylogeny. However, the structural organization of the receptor-binding spike complex and how the different symmetry mismatches are mediated between the spike-complex proteins are not clear. We determined the architecture of the PRD1 spike complex by using electron microscopy and three-dimensional image reconstruction of a series of PRD1 mutants. We constructed an atomic model for the full-length P5 spike protein by using comparative modeling. P5 was shown to be bound directly to the penton base protein P31. P5 and the receptor-binding protein P2 form two separate spikes, interacting with each other near the capsid shell. P5, with a tumor necrosis factor-like head domain, may have been responsible for host recognition before capture of the current receptor-binding protein P2.
authors.affiliation: Department of Biological and Environmental Sciences, Institute of Biotechnology, P.O. Box 65 (Viikinkaani 1), University of Helsinki, FI-0014, Helsinki, Finland.
authors.forename: Juha T
authors.initials: JT
authors.lastname: Huiskonen
authors.forename: Violeta
authors.initials: V
authors.lastname: Manole
authors.forename: Sarah J
authors.initials: SJ
authors.lastname: Butcher
mesh_terms: D025622:Bacteriophage PRD1 / Q000737:chemistry* / Q000648:ultrastructure; D036022:Capsid Proteins / Q000737:chemistry* / Q000648:ultrastructure; D020285:Cryoelectron Microscopy; D006026:Glycoside Hydrolases; D008958:Models, Molecular; D017376:Viral Tail Proteins / Q000737:chemistry* / Q000648:ultrastructure
chemical_list: D036022:Capsid Proteins; D017376:Viral Tail Proteins; C413083:protein P5, bacteriophage PRD1; D006026:Glycoside Hydrolases; C083268:tailspike protein, bacteriophage