title: The structure of gene product 6 of bacteriophage T4, the hinge-pin of the baseplate.
abstract: The baseplate of bacteriophage T4 is a multicomponent protein complex, which controls phage attachment to the host. It assembles from six wedges and a central hub. During infection the baseplate undergoes a large conformational change from a dome-shaped to a flat, star-shaped structure. We report the crystal structure of the C-terminal half of gene product (gp) 6 and investigate its motion with respect to the other proteins during the baseplate rearrangement. Six gp6 dimers interdigitate, forming a ring that maintains the integrity of the baseplate in both conformations. One baseplate wedge contains an N-terminal dimer of gp6, whereas neighboring wedges are tied together through the C-terminal dimer of gp6. The dimeric interactions are preserved throughout the rearrangement of the baseplate. However, the hinge angle between the N- and C-terminal parts of gp6 changes by approximately 15 degrees , accounting for a 10 A radial increase in the diameter of the gp6 ring.
authors.affiliation: Department of Biological Sciences, Purdue University, 915 W. State Street, West Lafayette, IN 47907-2054, USA.
authors.forename: Anastasia A
authors.initials: AA
authors.lastname: Aksyuk
authors.forename: Petr G
authors.initials: PG
authors.lastname: Leiman
authors.forename: Mikhail M
authors.initials: MM
authors.lastname: Shneider
authors.forename: Vadim V
authors.initials: VV
authors.lastname: Mesyanzhinov
authors.forename: Michael G
authors.initials: MG
authors.lastname: Rossmann
mesh_terms: D000595:Amino Acid Sequence; D017122:Bacteriophage T4 / Q000235:genetics*; D020285:Cryoelectron Microscopy; D003460:Crystallization; D019281:Dimerization; D005814:Genes, Viral; D006023:Glycoproteins / Q000235:genetics* / Q000502:physiology* / Q000648:ultrastructure; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D014764:Viral Proteins / Q000235:genetics* / Q000502:physiology* / Q000648:ultrastructure
chemical_list: D006023:Glycoproteins; D014764:Viral Proteins