A Quantitative Characterization of the Chemotactic Behavior of Tethered Bacillus Subtilis Cells

279 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2002.Studying the quantitative behavior of tethered B. subtilis cells led to the discovery of new functional features of several chemotaxis proteins. Results are presented that demonstrate that the functional roles of CheW and CheV are different, and that the response regulator domain of CheV plays an important role in adaptation to the addition of stimulus. Deleting the methylesterase CheB from the system had a profound effect on chemotaxis in the presence of a stimulus, as well as an effect on the duration of rotational events in the absence of stimulus. One of the most interesting discoveries was the antagonistic roles of CheC and CheD in biasing the probability of smooth swimming. CheC was identified as a regulator of the energy barrier associated with flagellar switching, and so is presumed to contact the flagellar switch. Since CheC also interacts with the receptor complex, it may migrate between the switch and receptor complexes during adaptation.U of I OnlyRestricted to the U of I community idenfinitely during batch ingest of legacy ETD