Our long term objective is to understand the mechanism of sensory transduction during chemotaxis in Bacillus subtilis. The chemotaxis systems of Bacillus subtilis and Escherichia coli share some features. However, there are several basic differences. Methyl transfer reactions occur between proteins upon excitation by both attractants and repellents and methanol is released to bring about adaptation to both these stimuli. In Halobacterium halobium, one of the archebacteria, methanol release also occurs for all types of stimuli. E. coli does not use methyl transfer between proteins. The methyl-accepting chemotaxis proteins (MCPs), the receptors, in E. coli are around 60 kD, but the major MCPs of B. subtilis are 79, 87, and 97 kD. These are more similar in size to those of Halobacterium halobium. Thus, there is reason to believe that the underlying methylation mechanism of chemotaxis differs between B. subtilis and E. coli but there may be more similarity between B. subtilis and H. halobium. This similarity to H. halobium may have far-reaching significance. The archebacteria are more closely related to eucaryotic cells than to true bacteria; so that there is the possibility that methyl transfer reactions might play unsuspected roles in sensory transduction in eucaryotic cells. We soon will be finishing the cloning and sequencing of che/fla genes. We will then inactivate them to define from in vivo experiments the roles of the corresponding proteins in chemotaxis. We will express them in an E. coli expression system and purify them. We have purified the three major MCPs of B. subtilis, reconstituted them into lipid vesicles, and methylated them. We will reconstitute phosphoryl and methyl transfer pathways and observe effect of attractant and repellent on enzymatic activities and stoichiometry of complexes of chemotaxis proteins. We will use site-directed mutagenesis and casette mutagenesis to delineate structure/function relationships among chemotaxis proteins. Finally, we will study regulation of the major che/fla operon. This operon is over 26 kb and contains at least 27 genes. We will also examine the mechanism by which both hag and mot transcription and methanol formation on chemotactic stimulation depend on the morphology of the basal body.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM054365-16
Application #
2713754
Study Section
Special Emphasis Panel (ZRG5-MBC-1 (02))
Project Start
1983-08-01
Project End
2000-05-31
Budget Start
1998-06-01
Budget End
1999-05-31
Support Year
16
Fiscal Year
1998
Total Cost
Indirect Cost
Name
University of Illinois Urbana-Champaign
Department
Biochemistry
Type
Schools of Arts and Sciences
DUNS #
041544081
City
Champaign
State
IL
Country
United States
Zip Code
61820
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Koirala, Santosh; Mears, Patrick; Sim, Martin et al. (2014) A nutrient-tunable bistable switch controls motility in Salmonella enterica serovar Typhimurium. MBio 5:e01611-14
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Josenhans, Christine; Jung, Kirsten; Rao, Christopher V et al. (2014) A tale of two machines: a review of the BLAST meeting, Tucson, AZ, 20-24 January 2013. Mol Microbiol 91:6-25
Glekas, George D; Mulhern, Brendan J; Kroc, Abigail et al. (2012) The Bacillus subtilis chemoreceptor McpC senses multiple ligands using two discrete mechanisms. J Biol Chem 287:39412-8
Yuan, Wei; Glekas, George D; Allen, George M et al. (2012) The importance of the interaction of CheD with CheC and the chemoreceptors compared to its enzymatic activity during chemotaxis in Bacillus subtilis. PLoS One 7:e50689
Glekas, George D; Plutz, Matthew J; Walukiewicz, Hanna E et al. (2012) Elucidation of the multiple roles of CheD in Bacillus subtilis chemotaxis. Mol Microbiol 86:743-56
Cannistraro, Vincent J; Glekas, George D; Rao, Christopher V et al. (2011) Cellular stoichiometry of the chemotaxis proteins in Bacillus subtilis. J Bacteriol 193:3220-7
Wu, Kang; Walukiewicz, Hanna E; Glekas, George D et al. (2011) Attractant binding induces distinct structural changes to the polar and lateral signaling clusters in Bacillus subtilis chemotaxis. J Biol Chem 286:2587-95
Glekas, George D; Cates, Joseph R; Cohen, Theodore M et al. (2011) Site-specific methylation in Bacillus subtilis chemotaxis: effect of covalent modifications to the chemotaxis receptor McpB. Microbiology 157:56-65

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