Title: Function of a SoxR-regulated ABC transporter and monooxygenase enzyme in S.
Authors: Han Wang and Monica Chander
Affiliation: Biology Department, Bryn Mawr College, Bryn Mawr, PA
In enterobacteria, the redox-sensing transcription factor SoxR mediates a global
oxidative stress response against toxic redox-cycling compounds. In the non-enteric
bacteria Pseudomonas aeruginosa and Streptomyces coelicolor, however, SoxR is
predicted to mediate a more specific response against endogenously produced redoxactive
metabolites. We have previously shown that, in S. coelicolor, activation of five
SoxR-regulated genes is dependent on the presence of the endogenously produced redoxactive
antibiotic actinorhodin (Act). One of these genes, SCO7008, encodes a putative
ABC transporter, while a second, SCO1909, encodes a monoxygenase that shares
similarity with an enzyme that functions in the Act biosynthetic pathway. These
observations have led to the hypothesis that SoxR assists in protecting S. coelicolor from
the toxic effects of Act. The goal of this study is to determine how SCO7008 and
SCO1909 contribute to SoxR’s detoxification mechanisms. These two genes will be
deleted (individually and in combination) and the phenotype of the resulting mutants will
be analyzed in Act-producing and Act-deficient backgrounds.