title: Crystal structure of a heat and protease-stable part of the bacteriophage T4 short tail fibre.
abstract: Adsorption of T4 bacteriophage to the Escherichia coli host cell is mediated by six long and six short tail fibres. After at least three long tail fibres have bound, short tail fibres extend and bind irreversibly to the core region of the host cell lipopolysaccharide (LPS), serving as inextensible stays during penetration of the cell envelope by the tail tube. The short tail fibres consist of a parallel, in-register, trimer of gene product 12 (gp12). The 1.9 A crystal structure of a heat and protease-stable fragment of gp12 reveals three new folds: a central right-handed triple beta-helix, a globular C-terminal domain containing a beta-sandwich and an N-terminal beta-structure reminiscent of but different from the adenovirus triple beta-spiral. The centre of the C-terminal domain shows weak homology to gp11, a trimeric protein connecting the short fibre to the base-plate, suggesting that the trimerisation motifs of gp11 and gp12 are similar. Repeating sequence motifs suggest that the N-terminal beta-structure extends further towards the N terminus and is conserved in the long tail fibre proteins gp34 and gp37.
authors.affiliation: Gorlaeus Laboratoria, Leiden University, Einsteinweg 55, NL-2300 RA Leiden, Netherlands. m.vanraaij@chem.leidenuniv.nl
authors.forename: M J
authors.initials: MJ
authors.lastname: van Raaij
authors.forename: G
authors.initials: G
authors.lastname: Schoehn
authors.forename: M R
authors.initials: MR
authors.lastname: Burda
authors.forename: S
authors.initials: S
authors.lastname: Miller
mesh_terms: D000595:Amino Acid Sequence; D017122:Bacteriophage T4 / Q000737:chemistry* / Q000648:ultrastructure; D018360:Crystallography, X-Ray; D010450:Endopeptidases / Q000378:metabolism*; D006358:Hot Temperature; D008854:Microscopy, Electron; D008958:Models, Molecular; D008969:Molecular Sequence Data; D020836:Protein Structure, Quaternary; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D016415:Sequence Alignment; D015678:Viral Structural Proteins / Q000737:chemistry* / Q000378:metabolism* / Q000648:ultrastructure
chemical_list: D015678:Viral Structural Proteins; C080832:gp12 protein, Enterobacteria phage T4; D010450:Endopeptidases