Structure and Function of Bordetella Transcription Factor BpsR

Biofilms are multicellular bacterial populations encapsulated in a self-produced or host-derived opaque matrix composed of polysaccharides, proteins, and extracellular DNA. They help bacteria persist, resist and evade host immune response. In Bordetella, the Bordetella polysaccharide (Bps) is a crucial polysaccharide component of a mature biofilm. Bps production is controlled by the bps locus. This locus contains genes bpsA-D whose expression is necessary for appropriate Bps function. The bpsA promoter is under repressive regulation by a MarR-family transcription factor Bordetella polysaccharide regulator, BpsR. BpsR binding inhibits expression of the bps locus, and leads to a decrease in polysaccharide available for biofilm formation. The goal of this thesis was to evaluate BpsR regulation at two surface exposed cysteine residues, as well as analyze residues within the (winged) Helix-turn-Helix DNA binding domain likely to confer BpsR affinity for the bpsA promoter. Sequence alignment of BpsR-like proteins revealed a novel CxxxxxxxC motif in BpsR that contributes to regulation of DNA binding. Additionally, it was found that glutathione acts as a positive allosteric effector for DNA binding. Mutational analyses of BpsR also reveal a role for residues Q75, R79, and R101 in DNA binding.

Grantor dc:publisher

Wake Forest University

Year dc:date.issued

2016

Author dc:creator

• Dodge, Brittney

• Biofilm

Language dc:language.iso

en

Handle dc:identifier.uri

http://hdl.handle.net/10339/59311

OAI identifier oai:identifier

oai:wakespace.lib.wfu.edu:10339/59311