Enrichment of Low Abundance Proteins and Isolation of the Novel Serine/Threonine Phosphatase, YghJ, from Shiga Toxin-Producing Escherichia Coli O91:H21
Date of Award
Master of Science
Dr. Maria E. Scott
Dr. Silvia Rossbach
Dr. Susan Stapleton
Masters Thesis-Campus Only
To examine the secreted protein profile of Shiga toxin-producing Escherichia coli (STEC) we developed a method to enrich for low abundance secreted proteins. Rotary evaporation in combination with conventional spin column concentration achieved protein enrichment 10-fold greater than that acquired by the traditional trichloroacetic acid protein precipitation method. Analysis of the enriched secreted protein fraction led to the discovery of a protein designated as YghJ. Genetic homology analysis revealed that YghJ is a serine/threonine phosphatase-like protein. Serine/threonine phosphatases have not previously been discovered in Escherichia coli and are rare in bacteria. The probable serine/threonine phosphatase activity of YghJ suggests that the protein may play a role in the regulation of stress factors produced by E. coli during times of nutrient deprivation.
Trumble, Chad, "Enrichment of Low Abundance Proteins and Isolation of the Novel Serine/Threonine Phosphatase, YghJ, from Shiga Toxin-Producing Escherichia Coli O91:H21" (2009). Masters Theses. 302.