In Vitro Analysis of Hin-mediated Site-specific Recombination
This extract was created in the absence of an abstract.
Excerpt
Populations of Salmonella can express two different flagellar antigens (Stocker 1949). Individual organisms oscillate from one flagellin type to another at a frequency that ranges from 10−3 10−5 per cell per generation (Lederberg and Iino 1956). This switch is mediated by an inversion of a 995-bp segment of DNA within the Salmonella chromosome (see Fig. 1). In one orientation (ON), a promoter within the invertible segment directs the expression of the H2 and rh1 genes. The product of the rh1 gene prevents expression of the unlinked H1 flagellin gene. In the OFF orientation, neither the H2 nor the rh1 repressor genes are expressed, and the H1 flagellin protein is produced (Zieg et al. 1977; Silverman et al. 1979).
The invertible region from Salmonella has been cloned into Escherichia coli where it is also capable of undergoing site-specific recombination. Genetic analysis has demonstrated that the inversion is dependent upon a gene,...
