Phage HK022 Roi protein inhibits phage lytic growth in Escherichia coli integration host factor mutants.

AUTOR(ES)

Clerget, M

RESUMO

Temperate coliphage HK022 requires integration host factor (IHF) for lytic growth. The determinant responsible for this requirement was identified as a new gene (roi) located between genes P and Q. This gene encodes a DNA-binding protein (Roi) containing a helix-turn-helix motif. We have shown that Roi binds a site within its own gene that is closely linked to an IHF binding site. By gel retardation experiments, we have found that IHF binding stabilizes the interaction of Roi with its gene. We have isolated three independent phage mutants that are able to grow on an IHF- host. They carry different mutations scattered in the roi gene and specifying single amino-acid changes. The interactions of all three Roi mutant proteins with the Roi binding site differed from that of the wild type. Roi displays strong similarities, in its C-terminal half, to two putative DNA-binding proteins of bacteriophage P1: Ant1 and KilA. The mode of action of the Roi protein and the possibility that IHF is modulating the expression and/or the action of Roi are discussed.

Documentos Relacionados

• Escherichia coli NusA is required for efficient RNA binding by phage HK022 Nun protein
• The Nun protein of bacteriophage HK022 inhibits translocation of Escherichia coli RNA polymerase without abolishing its catalytic activities
• Phage HK022 Nun protein represses translation of phage λ N (transcription termination/translation repression)
• Interaction between the phage HK022 Nun protein and the nut RNA of phage lambda.
• A segment of the phage HK022 chromosome is a mosaic of other lambdoid chromosomes.