Sequence and characterization of Bacillus subtilis CheB, a homolog of Escherichia coli CheY, and its role in a different mechanism of chemotaxis.
The Bacillus subtilis gene encoding CheB, which is homologous to Escherichia coli CheY, the regulator of flagellar rotation, has been cloned and sequenced. It has been verified, using a phage T7 expression system, by showing that a small protein, the same size as E. coli CheY, is actually made from this DNA. Despite the fact that the two proteins are 36% identical, with many highly conserved residues, they appear to play different roles. Unlike CheY null mutants, which swim smoothly, CheB null mutants tumble incessantly. However, a CheB point mutant swims smoothly, even in the presence of a plasmid bearing cheB, which restores the null mutants to wild type. Expression of CheB in wild type B. subtilis makes the cells exhibit more tumbling. Since both absence of CheB and presence of high levels of CheB cause tumbling, CheB appears to be required, in certain circumstances, for both smooth swimming and tumbling. Expression in wild type E. coli makes the cells smooth swimmers and strongly inhibits chemotaxis.
Bischoff
D S
DS
Department of Biochemistry, College of Medicine, University of Illinois, Urbana 61820.
Ordal
G W
GW
D000595:Amino Acid Sequence; D001412:Bacillus subtilis / Q000235:genetics* / Q000502:physiology; D001426:Bacterial Proteins / Q000235:genetics*; D001483:Base Sequence; D015139:Blotting, Southern; D002633:Chemotaxis; D004269:DNA, Bacterial / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics; D029968:Escherichia coli Proteins; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D008565:Membrane Proteins / Q000235:genetics*; D000072236:Methyl-Accepting Chemotaxis Proteins; D008969:Molecular Sequence Data; D009154:Mutation; D010957:Plasmids; D015183:Restriction Mapping; D016415:Sequence Alignment
D001426:Bacterial Proteins; D004269:DNA, Bacterial; D029968:Escherichia coli Proteins; D008565:Membrane Proteins; D000072236:Methyl-Accepting Chemotaxis Proteins; C000607606:cheY protein, E coli; C069656:CheB protein, Bacteria