The Antirepressor Needed for Induction of Linear Plasmid-Prophage N15 Belongs to the SOS Regulon

  title={The Antirepressor Needed for Induction of Linear Plasmid-Prophage N15 Belongs to the SOS Regulon},
  author={Andrey V. Mardanov and Nikolai V. Ravin},
  journal={Journal of Bacteriology},
  pages={6333 - 6338}
ABSTRACT The physiological conditions and molecular interactions that control phage production have been studied in only a few families of temperate phages. We investigated the mechanisms that regulate activation of lytic development in lysogens of coliphage N15, a prophage that is not integrated into the host chromosome but exists as a linear plasmid with covalently closed ends. We identified the N15 antirepressor gene, antC, and showed that its product binds to and acts against the main phage… 

Phage-Borne Factors and Host LexA Regulate the Lytic Switch in Phage GIL01

A model in which host LexA binds to dinBox sequences in GIL01, repressing phage gene expression during lysogeny and providing the switch necessary to enter lytic development is supported.

Bacteriophage Crosstalk: Coordination of Prophage Induction by Trans-Acting Antirepressors

Identification of non-cleavable gfoR/gtgR homologues in a large variety of bacterial genomes suggests that antirepression-mediated induction is far more common than previously recognized.

Studies on the gene regulation involved in the lytic-lysogenic switch in Staphylococcus aureus temperate bacteriophage Phi11.

The results indicate that Gp07 functions as a novel antirepressor and regulates the developmental pathway of Phi11 by enhancing the binding of the Cro repressor protein to its cognate operator and suggests that Phi11 prophage induction is different from other bacteriophages.

Small protein modules dictate prophage fates during polylysogeny

Exposure of the polylysogens studied here to different induction scenarios reveals that mixed phage populations emerge following DNA damage, however, induction through the SOS-independent module drives near-exclusive production of the phage sensitive to that specific cue.

The Molecular Switch of Telomere Phages: High Binding Specificity of the PY54 Cro Lytic Repressor to a Single Operator Site

The location of the PY54 Cro binding site and of the identified promoters suggests that the lytic repressor suppresses cI transcription but not its own synthesis, which indicates an unexpected diversity of the growth regulation mechanisms in lambda-related phages.

The Use and Abuse of LexA by Mobile Genetic Elements.

Extended Function of Plasmid Partition Genes: the Sop System of Linear Phage-Plasmid N15 Facilitates Late Gene Expression

The results indicate that the N15 Sop system has a dual role: partition and regulation of late gene transcription during lytic growth.

Bacteriophage GIL01 gp7 interacts with host LexA repressor to enhance DNA binding and inhibit RecA-mediated auto-cleavage

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N15: the linear phage-plasmid.



LexA cleavage is required for CTX prophage induction.

Functional characterization of the repA replication gene of linear plasmid prophage N15.

The anti‐immunity system of phage‐plasmid N15: identification of the antirepressor gene and its control by a small processed RNA

The N15 anti‐immunity system is structurally and functionally similar to the anti-immunities system of bacteriophage P1 and to the immunity system of satellite phage P4.

Defining the SOS operon of coliphage 186.

The LexA-controlled operon of coliphage 186 that carries the tum gene, whose product is necessary for UV induction of the 186 prophage, is sequenced and identified as orf95, the product of the full-length Orf95 protein.

Characterization of the primary immunity region of the Escherichia coli linear plasmid prophage N15

The organization of these regulatory elements suggests that N15 plasmid replication is controlled not only by CB but also by an antisense RNA and by a balance between termination and antitermination.

Autodigestion of lexA and phage lambda repressors.

  • J. W. Little
  • Biology
    Proceedings of the National Academy of Sciences of the United States of America
  • 1984
It is shown here that, under certain conditions, specific in vitro cleavage of highly-purified lexA protein can take place in the absence of recA protein, indicating that autodigestion and recA-dependent cleavage follow, at least in part, a similar reaction pathway.

Genomic sequence and analysis of the atypical temperate bacteriophage N15.

The unique structure of the N15 genome suggests that the large global population of bacteriophages may exhibit a much greater diversity of genomic architectures than was previously recognized.

Lytic Mode of Lambda Development

The role of the λ N function in regulating the lytic cycle is stressed, in part, because N function is among the best characterized regulatory proteins and its action typifies a mechanism of regulation based upon transcription termination-antitermination.

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Mechanism of action of Salmonella phage P22 antirepressor.