Jason R Kirby

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We characterized mutants in two novel genes of Bacillus subtilis, cheC and cheD. Mutants in CheC had a high smooth swimming bias and exhibited poor adaptation to positive stimuli. Analysis of tethered cells revealed two distinct subpopulations which differ in their prestimulus bias and extent of adaptation. The receptors, the methyl-accepting chemotaxis(More)
Chemotaxis by Bacillus subtilis requires the inter-acting chemotaxis proteins CheC and CheD. In this study, we show that CheD is absolutely required for a behavioural response to proline mediated by McpC but is not required for the response to asparagine mediated by McpB. We also show that CheC is not required for the excitation response to asparagine(More)
For the Gram-positive organism Bacillus subtilis, chemotaxis to the attractant asparagine is mediated by the chemoreceptor McpB. In this study, we show that rapid net demethylation of B. subtilis McpB results in the immediate production of methanol, presumably due to the action of CheB. We also show that net demethylation of McpB occurs upon both addition(More)
The 20 common amino acids act as attractants during chemotaxis by the Gram-positive organism Bacillus subtilis. In this study, we report that all amino acids induce B. subtilis to produce methanol both upon addition and removal of the chemoeffector. Asparagine-induced methanol production is specific to the McpB receptor and aspartate-induced methanol(More)
The methyl-accepting chemotaxis protein, McpB, is the sole receptor mediating asparagine chemotaxis in Bacillus subtilis. In this study, we show that wild-type B. subtilis cells contain approximately 2,000 copies of McpB per cell, that these receptors are localized polarly, and that titration of only a few receptors is sufficient to generate a detectable(More)
The Bacillus subtilis gene encoding CheB (cheBB), the chemotactic methylesterase, has been sequenced. The 39-kDa protein which resulted from the expression of cheBB, using a T7 expression system was consistent with the predicted open reading frame. CheBB shares 39.5% identity with Escherichia coli CheBE and can complement a cheBE null mutant. CheBB is(More)
A set of chemotaxis mutants of Bacillus subtilis was complemented by using SP beta c2 transducing bacteriophage either containing cloned segments of DNA or derived from abnormal excision of SP beta c2 dl2::Tn917 inserted into the chemotaxis region. Representative mutants were characterized in capillary assays for chemotaxis toward four amino acids and(More)
If Bacillus subtilis is incubated in radioactive methionine in the absence of protein synthesis, the methyl-accepting chemotaxis proteins (MCPs) become radioactively methylated. If the bacteria are further incubated in excess nonradioactive methionine ("cold-chased") and then given the attractant aspartate, the MCPs lose about half of their radioactivity(More)
Modulation of autotaxin (ATX), the lysophospholipase D enzyme that produces lysophosphatidic acid, with small-molecule inhibitors is a promising strategy for blocking the ATX-lysophosphatidic acid signaling axis. Although discovery campaigns have been successful in identifying ATX inhibitors, many of the reported inhibitors target the catalytic cleft of(More)
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