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2010

Theses and Dissertations

Alginate

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Full-Text Articles in Medicine and Health Sciences

Exploring The Mechanism Of Alginate Acetylation In Pseudomonas Aeruginosa, Janice Paletta Apr 2010

Exploring The Mechanism Of Alginate Acetylation In Pseudomonas Aeruginosa, Janice Paletta

Theses and Dissertations

The opportunistic pathogen P. aeruginosa is the leading cause of morbidity and mortality in cystic fibrosis patients. During chronic infection of the cystic fibrosis lung, P. aeruginosa undergoes conversion to a mucoid phenotype, constitutively producing the exopolysaccharide alginate, composed of the uronic acids D-mannuronate and L-guluronate. This alginate production contributes significantly to virulence in the cystic fibrosis lung. Evidence suggests that the acetylation state of the mannuronate component of the alginate influences the ability of components of the immune system to phagocytose the organism. To garner new and relevant information regarding the mechanism of alginate acetylation in Pseudomonas aeruginosa, a …


Alternative Regulation Of The Alginate Algd Operon By An Activated Algb In Nonmucoid Pseudomonas Aeruginosa Is Dependent On Sigma 54, Jean Kim Jan 2010

Alternative Regulation Of The Alginate Algd Operon By An Activated Algb In Nonmucoid Pseudomonas Aeruginosa Is Dependent On Sigma 54, Jean Kim

Theses and Dissertations

Alginate overproduction by Pseudomonas aeruginosa, which causes a mucoid phenotype, is a major virulence factor associated with chronic pulmonary infections in cystic fibrosis patients. Expression of the algD operon for alginate biosynthesis requires three major regulators in association with the ECF sigma factor, σ22, in mucoid strains that are typically defective in anti-sigma factor, MucA. One such algD regulator is AlgB, a member of the NtrC family of two-component systems, which typically utilize σ54. However, neither σ54 nor the cognate sensor kinase (KinB) of AlgB are required for algD expression in such mucoid strains. I hypothesized that KinB-phosphorylated AlgB must …