title: An accessory role for Escherichia coli integration host factor: characterization of a lambda mutant dependent upon integration host factor for DNA packaging.
abstract: Bacteriophage lambda grows lytically on Escherichia coli defective for integration host factor, a protein involved in lambda site-specific recombination and the regulation of gene expression. We report the characterization of a mutant, lambda cos154, that, unlike wild-type lambda, is defective for growth in integration host factor-defective E. coli. The cis-dominant mutation in lambda cos154 is a single base pair change in a region of hyphenated dyad symmetry close to the lambda left cohesive end; this mutation prevents DNA packaging. We propose the following two alternative roles for this site in lambda DNA packaging: (i) to bind an E. coli accessory protein required in the absence of integration host factor or (ii) to bind the phage-encoded terminase protein that is essential for DNA packaging.
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics*; D010582:Bacteriophage lambda / Q000235:genetics / Q000254:growth & development*; D004268:DNA-Binding Proteins / Q000235:genetics*; D004926:Escherichia coli / Q000235:genetics*; D019426:Integrases; D009154:Mutation; D014764:Viral Proteins / Q000235:genetics*; D014779:Virus Replication
chemical_list: D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; D014764:Viral Proteins; D019426:Integrases