Location
University of Nevada, Las Vegas
Start Date
3-8-2010 9:00 AM
End Date
3-8-2010 12:00 PM
Description
The omptin family of proteins consists of proteases which lie in the outer membrane of some gram-negative, pathogenic bacteria such as Escherichia coli (OmpT), Shigella flexneri (IcsP), Salmonella typhimurium (PgtE), and Yersinia pestis (Pla). These proteases are highly conserved, sharing approximately 50% sequence identity and a β-barrel shape (fig. 1D). The differences in the structure of these four proteins are in the surface-exposed loop region surrounding the active site, but not in the active site itself [4]. These proteases are important for the virulence of many bacteria. For example, OmpT of E. coli cleaves an antimicrobial peptide secreted by epithelial cells of the urinary tract [5]; IcsP of S. flexneri regulates IcsA, which uses the host’s actin to allow motility of the bacterium [6]; PgtE of S. typhimurium helps the bacterium evade the immune system by cleaving the α-helical cationic antimicrobial peptides [1]; and, Pla of Y. pestis enhances bacterial migration through tissue barriers by cleaving plasminogen [4]. Previous work [2] has shown that the omptin proteins of E. coli and S. typhimurium do not cleave IcsA in the same manner as IcsP in S. flexneri. Differences in the cleavage of IcsA may be due to the differences in surface-exposed loops of the protease or in its LPS binding motif [2]. Determining whether the surface-exposed loops of a protein affects its function could lead to a better understanding of this protein’s function and how it has evolved to serve different functions in different bacterial pathogens.
Keywords
Amino acid sequence; Bacteria; Genetic code; Proteins -- Analysis; Proteolytic enzymes
Disciplines
Genetics and Genomics | Life Sciences | Microbiology
Language
English
Modifying the amino acid sequence in the surface-exposed loops of the omptin family of proteins to determine their effect on function
University of Nevada, Las Vegas
The omptin family of proteins consists of proteases which lie in the outer membrane of some gram-negative, pathogenic bacteria such as Escherichia coli (OmpT), Shigella flexneri (IcsP), Salmonella typhimurium (PgtE), and Yersinia pestis (Pla). These proteases are highly conserved, sharing approximately 50% sequence identity and a β-barrel shape (fig. 1D). The differences in the structure of these four proteins are in the surface-exposed loop region surrounding the active site, but not in the active site itself [4]. These proteases are important for the virulence of many bacteria. For example, OmpT of E. coli cleaves an antimicrobial peptide secreted by epithelial cells of the urinary tract [5]; IcsP of S. flexneri regulates IcsA, which uses the host’s actin to allow motility of the bacterium [6]; PgtE of S. typhimurium helps the bacterium evade the immune system by cleaving the α-helical cationic antimicrobial peptides [1]; and, Pla of Y. pestis enhances bacterial migration through tissue barriers by cleaving plasminogen [4]. Previous work [2] has shown that the omptin proteins of E. coli and S. typhimurium do not cleave IcsA in the same manner as IcsP in S. flexneri. Differences in the cleavage of IcsA may be due to the differences in surface-exposed loops of the protease or in its LPS binding motif [2]. Determining whether the surface-exposed loops of a protein affects its function could lead to a better understanding of this protein’s function and how it has evolved to serve different functions in different bacterial pathogens.
Comments
Poster research sponsored by Department and Grant Supported Students