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Medicine and Health Sciences Commons

Open Access. Powered by Scholars. Published by Universities.®

Medical Microbiology

2010

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Articles 1 - 2 of 2

Full-Text Articles in Medicine and Health Sciences

H-Ns Binding And Repression Of The Ctx Promoter In Vibrio Cholerae, Emily A. Stonehouse, Robin R. Hulbert, Melinda B. Nye, Karen Skorupski, Ronald K. Taylor Dec 2010

H-Ns Binding And Repression Of The Ctx Promoter In Vibrio Cholerae, Emily A. Stonehouse, Robin R. Hulbert, Melinda B. Nye, Karen Skorupski, Ronald K. Taylor

Dartmouth Scholarship

Expression of the ctx and tcp genes, which encode cholera toxin and the toxin coregulated pilus, the Vibrio cholerae O1 virulence determinants having the largest contribution to cholera disease, is repressed by the nucleoid-associated protein H-NS and activated by the AraC-like transcriptional regulator ToxT. To elucidate the molecular mechanism by which H-NS controls transcription of the ctxAB operon, H-NS repression and binding were characterized by using a promoter truncation series, gel mobility shift assays, and DNase I footprinting. Promoter regions found to be important for H-NS repression correlated with in vitro binding. Four main H-NS binding regions are present at …


Structure Of Vibrio Cholerae Toxt Reveals A Mechanism For Fatty Acid Regulation Of Virulence Genes, Michael J. Lowden, Karen Skorupski, Maria Pellegrini, Michael G. Chiorazzo, Ronald K. Taylor, F. Jon Kull Feb 2010

Structure Of Vibrio Cholerae Toxt Reveals A Mechanism For Fatty Acid Regulation Of Virulence Genes, Michael J. Lowden, Karen Skorupski, Maria Pellegrini, Michael G. Chiorazzo, Ronald K. Taylor, F. Jon Kull

Dartmouth Scholarship

Cholera is an acute intestinal infection caused by the bacterium Vibrio cholerae. In order for V. cholerae to cause disease, it must produce two virulence factors, the toxin-coregulated pilus (TCP) and cholera toxin (CT), whose expression is controlled by a transcriptional cascade culminating with the expression of the AraC-family regulator, ToxT. We have solved the 1.9 A resolution crystal structure of ToxT, which reveals folds in the N- and C-terminal domains that share a number of features in common with AraC, MarA, and Rob as well as the unexpected presence of a buried 16-carbon fatty acid, cis-palmitoleate. The finding that …