Roles of cheY and cheZ gene products in controlling flagellar rotation in bacterial chemotaxis of Escherichia coli.

摘要: Abstract To understand output control in bacterial chemotaxis, we varied the levels of expression cellular cheY and cheZ genes found that overproduction corresponding proteins affected Escherichia coli swimming behavior. In absence other signal-transducing gene products, CheY made free-swimming cells tumble more frequently. A plot fraction population are tumbling versus concentration was hyperbolic, with half at 30 microM (25,000 copies per cell) monomers cytosol. Overproduction aspartate receptor (Tar) by 30-fold had a negligible effect on CheY-induced tumbling, so Tar does not sequester CheY. CheZ decreased all mutants except certain flaAII(cheC) mutants. chemotaxis inhibited tumbling. Models for as signal smooth-swimming to flagellar rotation discussed.