The bacteriophage lambda tail protein gpK is required for tail assembly. The activity of the protein can be found at the assembling tail tip and is believed to be localized to this structure. GpK is a 27 kDa protein that has sequence identity to two families of proteins: the Mov34 family of peptidases and the NlpC/P60 family of peptidoglycan endopeptidases. Point substitutions and complementation data confirm that gpK possesses each of these domains and that they can function in trans. When the Mov34 domain is inactivated tail assembly is disrupted whereas when the NlpC/P60 domain is inactivated tails assemble but are inactive. Evidence is presented here that the C-terminal domain possesses lytic activity in isolation but not when part of the full-length protein.

The bacteriophage lambda tail protein gpK is required for tail assembly. The activity of the protein can be found at the assembling tail tip and is believed to be localized to this structure. GpK is a 27 kDa protein that has sequence identity to two families of proteins: the Mov34 family of peptidases and the NlpC/P60 family of peptidoglycan endopeptidases. Point substitutions and complementation data confirm that gpK possesses each of these domains and that they can function in trans. When the Mov34 domain is inactivated tail assembly is disrupted whereas when the NlpC/P60 domain is inactivated tails assemble but are inactive. Evidence is presented here that the C-terminal domain possesses lytic activity in isolation but not when part of the full-length protein.

The bacteriophage lambda tail protein gpK is required for tail assembly. The activity of the protein can be found at the assembling tail tip and is believed to be localized to this structure. GpK is a 27 kDa protein that has sequence identity to two families of proteins: the Mov34 family of peptidases and the NlpC/P60 family of peptidoglycan endopeptidases. Point substitutions and complementation data confirm that gpK possesses each of these domains and that they can function in trans. When the Mov34 domain is inactivated tail assembly is disrupted whereas when the NlpC/P60 domain is inactivated tails assemble but are inactive. Evidence is presented here that the C-terminal domain possesses lytic activity in isolation but not when part of the full-length protein.