Superoxide Toxicity in Escherichia Coli

Very little is understood about the physiology of the periplasm. of gram negative bacteria. The presence of CuZnSOD within that compartment in several different species suggests that oxidative damage occurs there. We studied the regulation of sodC, the gene that encodes CuZnSOD, and the phenotypes of sodC mutants to determine its physiological role. We found that sodC is activated by RpoS in stationary phase, is repressed by Fnr and ArcA anaerobically, and is repressed when copper is unavailable. Mutants of sodC in E. coli and S. typhimurium suffer damage during aerobic growth from a cellular source of superoxide. The unknown damage sensitizes the mutants to subsequent challenges with H2O2. This result indicates that there is a role for CuZnSOD other than protection from exogenous superoxide sources. The cellular source of superoxide and its periplasmic target remain unknown.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Microbiology

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2015

Author dc:creator

• Gort, Amy Strohmeier

Contributors dc:contributor

• Imlay, James A.

• Chemistry, Biochemistry

Language dc:language

eng

Identifier

(MiAaPQ)AAI9912239

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/86736