CATABOLITE-REPRESSOR-LIKE PROTEIN REGULATES THE EXPRESSION OF A GENE UNDER THE CONTROL OF THE ESCHERICHIA-COLI LAC PROMOTER IN THE PLANT PATHOGEN XANTHOMONAS-CAMPESTRIS PV CAMPESTRIS
Sd. Soby et Mj. Daniels, CATABOLITE-REPRESSOR-LIKE PROTEIN REGULATES THE EXPRESSION OF A GENE UNDER THE CONTROL OF THE ESCHERICHIA-COLI LAC PROMOTER IN THE PLANT PATHOGEN XANTHOMONAS-CAMPESTRIS PV CAMPESTRIS, Applied microbiology and biotechnology, 46(5-6), 1996, pp. 559-561
Xanthomonas campestris pv. campestris, the causal agent of black-rot d
isease of cruciferous plants, and an important industrial microbe, was
able to express the Escherichia coli beta-glucuronidase reporter gene
(uidA) when fused to the E. coli lactose operon promoter on a wide-ho
st-range plasmid vector. The gene fusion is expressed constitutively a
t high levels in both complex and defined media using a wide range of
carbon sources, and is not repressible by glucose or inducible by the
gratuitous lac inducer isopropyl beta-D-thiogalactoside. An X. campres
tris campestris strain with a lesion in the clp (catabolite-repressor-
like protein) locus, and containing the plac/uidA fusion, was tested f
or beta-glucuronidase activity. We found that the expression of the pl
ac/uidA fusion gene is dependent on the presence of catabolite-repress
or-like protein, with an approximately 75% reduction of expression in
the clp -deficient mutant.