The lactococcal phages Tuc2009 and TP901-1 incorporate two alternate forms of their tail fiber into their virions for infection specialization

J Biol Chem. 2013 Feb 22;288(8):5581-90. doi: 10.1074/jbc.M112.444901. Epub 2013 Jan 8.

Abstract

Lactococcal phages Tuc2009 and TP901-1 possess a conserved tail fiber called a tail-associated lysin (referred to as Tal(2009) for Tuc2009, and Tal(901-1) for TP901-1), suspended from their tail tips that projects a peptidoglycan hydrolase domain toward a potential host bacterium. Tal(2009) and Tal(901-1) can undergo proteolytic processing mid-protein at the glycine-rich sequence GG(S/N)SGGG, removing their C-terminal structural lysin. In this study, we show that the peptidoglycan hydrolase of these Tal proteins is an M23 peptidase that exhibits D-Ala-D-Asp endopeptidase activity and that this activity is required for efficient infection of stationary phase cells. Interestingly, the observed proteolytic processing of Tal(2009) and Tal(901-1) facilitates increased host adsorption efficiencies of the resulting phages. This represents, to the best of our knowledge, the first example of tail fiber proteolytic processing that results in a heterogeneous population of two phage types. Phages that possess a full-length tail fiber, or a truncated derivative, are better adapted to efficiently infect cells with an extensively cross-linked cell wall or infect with increased host-adsorption efficiencies, respectively.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adsorption
  • Bacterial Adhesion
  • Computational Biology / methods
  • Hydrolysis
  • Lactococcus lactis / virology*
  • Mutagenesis
  • Peptidoglycan / chemistry
  • Plasmids / metabolism
  • Protein Binding
  • Protein Conformation
  • Protein Structure, Tertiary
  • Siphoviridae / genetics
  • Siphoviridae / metabolism*
  • Viral Tail Proteins / chemistry
  • Viral Tail Proteins / metabolism
  • Virion / metabolism

Substances

  • Peptidoglycan
  • Viral Tail Proteins