title: Bacteriophage Tuc2009 encodes a tail-associated cell wall-degrading activity.
abstract: Tuc2009 is a P335-type member of the tailed-phage supergroup Siphoviridae and was originally identified as a resident prophage of the gram-positive bacterium Lactococcus lactis UC509. A Tuc2009 gene designated tal2009 which is located within the morphogenic module was shown to specify a lytic activity within the 3' portion of its coding region. Comparative sequence analysis indicated that the cell wall-degrading part of Tal2009 is a member of the M37 protein family and that Tal2009 lacks a cell-binding domain, a finding supported by binding studies. Tal2009 appears to undergo self-mediated posttranslational processing in both L. lactis and Escherichia coli. Antibodies directed against a purified C-terminal portion of Tal2009 were used for immunoelectron microscopy, which showed that Tal2009 is located at the tail tip of Tuc2009. Antibody neutralization studies demonstrated that Tal2009-directed antibodies inhibited the ability of phage to mediate host lysis by more than 100-fold. These data indicate that tal2009 encodes a tail-associated lysin involved in localized cell wall degradation, thus allowing the Tuc2009 DNA injection machinery access to the membrane of its bacterial host.
authors.affiliation: National Food Biotechnology Centre and Department of Microbiology, National University of Ireland, Cork, Ireland.
authors.forename: John G
authors.initials: JG
authors.lastname: Kenny
authors.forename: Stephen
authors.initials: S
authors.lastname: McGrath
authors.forename: Gerald F
authors.initials: GF
authors.lastname: Fitzgerald
authors.forename: Douwe
authors.initials: D
authors.lastname: van Sinderen
mesh_terms: D002384:Catalysis; D002473:Cell Wall / Q000378:metabolism*; D004798:Enzymes / Q000737:chemistry*; D013294:Lactococcus lactis / Q000821:virology*; D039002:Prophages / Q000201:enzymology*; D011499:Protein Processing, Post-Translational; D017906:Siphoviridae / Q000201:enzymology*; D014764:Viral Proteins / Q000737:chemistry* / Q000378:metabolism
chemical_list: D004798:Enzymes; D014764:Viral Proteins