Acquisition and dissemination mechanisms of CTXΦ in Vibrio cholerae: New paradigm for dif residents

Figure 2 Replicative and integrative genomes of cholera toxin phage. Replicative genome of CTXΦ arranged in structurally and functionally distinct two modular structures RS2 and core. RS2 encoded proteins are essential for phage replication, integration and transcriptional regulation of phage genes. Core encoded proteins are essential for phage morphogenesis and virion production. Folded (+)ssDNA phage genome is essential for phage integration. Functional XerCD binding site, attP(+), is formed by complementary base pairing between attP1 and attP2 of (+)ssDNA of phage genome. We have used similar color codes for replicative and integrative phage genomes for easy understanding of genetic attributes of attP(+) region. CTXΦ: Cholera toxin phage; RS2: Repeat sequence 2.