1. Effect of LexA on Chromosomal Integration of CTXɸ in Vibrio cholerae.
- Author
-
Pant, Archana, Anbumani, D., Bag, Satyabrata, Mehta, Ojasvi, Kumar, Pawan, Saxena, Shruti, Nair, G. Balakrish, and Das, Bhabatosh
- Subjects
- *
VIBRIO cholerae , *BACTERIAL chromosomes , *CHOLERA toxin , *SINGLE-stranded DNA , *DNA-binding proteins , *GENETIC mutation , *GENE expression , *BACTERIAL genomes - Abstract
The genesis of toxigenic Vibrio cholerae involves acquisition of CTXɸ, a single-stranded DNA (ssDNA) filamentous phage that encodes cholera toxin (CT). The phage exploits host-encoded tyrosine recombinases (XerC and XerD) for chromosomal integration and lysogenic conversion. The replicative genome of CTXɸ produces ssDNA by rolling-circle replication, which may be used either for virion production or for integration into host chromosome. Fine-tuning of different ssDNA binding protein (Ssb) levels in the host cell is crucial for cellular functioning and important for CTXɸ integration. In this study, we mutated the master regulator gene of SOS induction, lexA, of V. cholerae because of its known role in controlling levels of Ssb proteins in other bacteria. CTXɸ integration decreased in cells with a ΔlexA mutation and increased in cells with an SOS-noninducing mutation, lexA (Ind-). We also observed that overexpression of host-encoded Ssb (VC0397) decreased integration of CTXɸ. We propose that LexA helps CTXɸ integration, possibly by fine-tuning levels of host- and phage-encoded Ssbs. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF