Dataset Information

Chaperone-protein interactions that mediate assembly of the bacteriophage lambda tail to the correct length.

ABSTRACT: Bacteriophage ? makes two proteins with overlapping amino acid sequences that are essential for tail assembly. These two proteins, gpG and gpGT, are related by a programmed translational frameshift that is conserved among diverse phages and functions in ? to ensure that gpG and the frameshift product gpGT are made in a molar ratio of approximately 30:1. Although both proteins are required and must be present in the correct ratio for assembly of functional tails, neither is present in mature tails. During ? tail assembly, major tail protein gpV polymerizes to form a long tube whose length is controlled by the tape measure protein gpH. We show that the "G" domains of gpG and gpGT bind to all or parts of tail length tape measure protein gpH and that the "T" domain of gpGT binds to major tail shaft subunit gpV, and present a model for how gpG and gpGT chaperone gpH and direct the polymerization of gpV to form a tail of the correct length.

SUBMITTER: Xu J

PROVIDER: S-EPMC3907469 | biostudies-literature | 2014 Mar

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Chaperone-protein interactions that mediate assembly of the bacteriophage lambda tail to the correct length.

Xu Jun J Hendrix Roger W RW Duda Robert L RL

Journal of molecular biology 20130730 5

Bacteriophage λ makes two proteins with overlapping amino acid sequences that are essential for tail assembly. These two proteins, gpG and gpGT, are related by a programmed translational frameshift that is conserved among diverse phages and functions in λ to ensure that gpG and the frameshift product gpGT are made in a molar ratio of approximately 30:1. Although both proteins are required and must be present in the correct ratio for assembly of functional tails, neither is present in mature tail ...[more]

PMID: 23911548

Similar Datasets

Project description:ICP2 is a virulent bacteriophage (phage) that preys on Vibrio cholerae. ICP2 was first isolated from cholera patient stool samples. Some of these stools also contained ICP2-resistant isogenic V. cholerae strains harboring missense mutations in the trimeric outer membrane porin protein OmpU, identifying it as the ICP2 receptor. In this study, we identify the ICP2 proteins that mediate interactions with OmpU by selecting for ICP2 host range mutants within infant rabbits infected with a mixture of wild-type and OmpU mutant strains. ICP2 host range mutants that can now infect OmpU mutant strains have missense mutations in the putative tail fiber gene gp25 and the putative adhesin gene gp23. Using site-specific mutagenesis, we show that single or double mutations in gp25 are sufficient to generate the host range mutant phenotype. However, at least one additional mutation in gp23 is required for robust plaque formation on specific OmpU mutants. Mutations in gp23 alone were insufficient to produce a host range mutant phenotype. All ICP2 host range mutants retained the ability to form plaques on wild-type V. cholerae cells. The strength of binding of host range mutants to V. cholerae correlated with plaque morphology, indicating that the selected mutations in gp25 and gp23 restore molecular interactions with the receptor. We propose that ICP2 host range mutants evolve by a two-step process. First, gp25 mutations are selected for their broad host range, albeit accompanied by low-level phage adsorption. Subsequent selection occurs for gp23 mutations that further increase productive binding to specific OmpU alleles, allowing for near-wild-type efficiencies of adsorption and subsequent phage multiplication. IMPORTANCE Concern over multidrug-resistant bacterial pathogens, including Vibrio cholerae, has led to renewed interest in phage biology and the potential for phage therapy. ICP2 is a genetically unique virulent phage isolated from cholera patient stool samples. It is also one of three phages in a prophylactic cocktail that have been shown to be effective in animal models of infection and the only one of the three that requires a protein receptor (OmpU). This study identifies an ICP2 tail fiber and a receptor binding protein and examines how ICP2 responds to the selective pressures of phage-resistant OmpU mutants. We found that this particular coevolutionary arms race presents fitness costs to both ICP2 and V. cholerae.

Dataset Information

Chaperone-protein interactions that mediate assembly of the bacteriophage lambda tail to the correct length.

Publications

Chaperone-protein interactions that mediate assembly of the bacteriophage lambda tail to the correct length.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets