Abstract Regulation of the aprE (Subtilisin) gene in abrB mutants of Bacillus subtilis

Jorge Olmos ^1*, Alejandro Sanchez¹ and Ramon DeAnda²

¹Molecular Microbiology Laboratory. Centro de Investigacion Cientifica y de Educacion Superior de Ensenada (CICESE),
Ensenada, Mexico.
²Molecular Microbiology Department, Instituto de Bioteenologia, UNAM. Cuernavaca, Mexico.

(Received 21 September 1998 / Accepted 27 October 1998)

Abstract.
The aprE gene of B. subtilis codes for the major extracellular alkaline protease subtilisin. Its expression is controlled by AbrB and other regulators. To understand the regulation of AbrB on subtilisin expression, an aprE::lacZ fusion was examined for the effects induced by combinations of the abrB, hpr and spoOA9V mutations over the aprE expression. We found that during sporulation on the abrB genetic background, the specific activity level of BGal was higher than in the wild type strain. The exception was the abrB/spo0A9Vdouble mutant which had a negative effect on aprE expression.

Keywords: SpoOA9V, hpr, subtilisin, B. subtitis, aprE::lacZ, over production