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On the role of Cro in lambda prophage induction.

ABSTRACT: The lysogenic state of bacteriophage lambda is exceptionally stable yet the prophage is readily induced in response to DNA damage. This delicate epigenetic switch is believed to be regulated by two proteins; the lysogenic maintenance promoting protein CI and the early lytic protein Cro. First, we confirm, in the native configuration, the previous observation that the DNA loop mediated by oligomerization of CI bound to two distinct operator regions (O(L) and O(R)), increases repression of the early lytic promoters and is important for stable maintenance of lysogeny. Second, we show that the presence of the cro gene might be unimportant for the lysogenic to lytic switch during induction of the lambda prophage. We revisit the idea that Cro's primary role in induction is instead to mediate weak repression of the early lytic promoters.

SUBMITTER: Svenningsen SL

PROVIDER: S-EPMC555511 | biostudies-literature | 2005 Mar

REPOSITORIES: biostudies-literature

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On the role of Cro in lambda prophage induction.

Svenningsen Sine L SL Costantino Nina N Court Donald L DL Adhya Sankar S

Proceedings of the National Academy of Sciences of the United States of America 20050223 12

The lysogenic state of bacteriophage lambda is exceptionally stable yet the prophage is readily induced in response to DNA damage. This delicate epigenetic switch is believed to be regulated by two proteins; the lysogenic maintenance promoting protein CI and the early lytic protein Cro. First, we confirm, in the native configuration, the previous observation that the DNA loop mediated by oligomerization of CI bound to two distinct operator regions (O(L) and O(R)), increases repression of the ear ...[more]

PMID: 15728734

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Extreme divergence between one-to-one orthologs: the structure of N15 Cro bound to operator DNA and its relationship to the λ Cro complex.

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