Mutants defective in bacterial chemotaxis show modified protein phosphorylation.
To examine the correlation between CheA phosphorylation and bacterial chemotaxis, cheA mutations leading to defects in chemotaxis were mapped and characterized. Mutant CheA proteins were tested in vitro for phosphorylation and were grouped into four classes: nonphosphorylated, partially phosphorylated, phosphorylated but not dephosphorylated by CheB and CheY, and phosphorylated and dephosphorylated. Nearly all the mutants were found to be defective in an aspect of phosphorylation. Furthermore, the mutant phenotypes were found to cluster in different regions of the cheA gene. We suggest that the CheA protein has three functional domains: one for interaction with CheB and CheY, a second for regulating phosphorylation and controlling the stability of the protein, and a third for receiving input signals regulating CheA activity.
Oosawa
K
K
Division of Biology, California Institute of Technology, Pasadena 91125.
Hess
J F
JF
Simon
M I
MI
D001426:Bacterial Proteins / Q000235:genetics; D002630:Chemotactic Factors / Q000235:genetics*; D002633:Chemotaxis; D004262:DNA Restriction Enzymes; D004926:Escherichia coli / Q000235:genetics* / Q000502:physiology; D029968:Escherichia coli Proteins; D005796:Genes; D005798:Genes, Bacterial; D000071677:Histidine Kinase; D007700:Kinetics; D008565:Membrane Proteins / Q000235:genetics* / Q000378:metabolism; D000072236:Methyl-Accepting Chemotaxis Proteins; D009154:Mutation; D010766:Phosphorylation
D001426:Bacterial Proteins; D002630:Chemotactic Factors; D029968:Escherichia coli Proteins; D008565:Membrane Proteins; D000072236:Methyl-Accepting Chemotaxis Proteins; C000607606:cheY protein, E coli; D000071677:Histidine Kinase; C000607608:cheA protein, E coli; D004262:DNA Restriction Enzymes