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Title:Copper/zinc Sods of Salmonella Typhimurium: Enzymatic Properties and Correlation to Pathogenesis
Author(s):Krishnakumar, Radha
Doctoral Committee Chair(s):Slauch, James M.
Department / Program:Microbiology
Discipline:Microbiology
Degree Granting Institution:University of Illinois at Urbana-Champaign
Degree:Ph.D.
Genre:Dissertation
Subject(s):Biology, Microbiology
Abstract:We have however, noted three significant differences between SodCI and SodCII: dimerization, tethering, and protease resistance. SodCI is a dimer and is not released from the periplasm by osmotic shock. Thus SodCI is "tethered" in the periplasm by some non-covalent interaction. In contrast, SodCII is monomeric and is quantitatively released by osmotic shock. Using site-directed mutagenesis we constructed a monomeric, fully active SodCI that is now released by osmotic shock. Thus dimerization is critical for tethering. Upon recombination of the monomeric SodCI allele into the normal chromosomal sodCI locus, we found that the resulting strain is avirulent when competed against the wild type strain, indicating that dimerization and/or tethering is crucial to virulence. Apparently, disrupting the dimeric conformation of SodCI also exposes some regions of the protein that renders SodCI sensitive to proteinase K digestion. This is in sharp contrast to wild-type SodCI, which is resistant to proteinase K. Thus it appears that SodCI must maintain its dimeric conformation, perhaps not for catalytic activity, but possibly to remain tethered within the periplasm in order to resist attack by host proteases, and also to retain its wild-type protease resistance.
Issue Date:2006
Type:Text
Language:English
Description:154 p.
Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2006.
URI:http://hdl.handle.net/2142/86687
Other Identifier(s):(MiAaPQ)AAI3242902
Date Available in IDEALS:2015-09-28
Date Deposited:2006


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