Biomaterial Database

CheZ mutants with enhanced ability to dephosphorylate CheY, the response regulator in bacterial chemotaxis. 1993

C Huang, and R C Stewart

Department of Microbiology and Immunology, McGill University, Montreal, Québec, Canada.

CheZ is a component of the chemotaxis signal-transduction pathway in Escherichia coli and Salmonella typhimurium. It is responsible for accelerating dephosphorylation of CheY and thereby antagonizing the tumble-promoting activity of CheY. In the absence of functional CheZ, cells are non-chemotactic and tumble constantly. We characterized the effects of two mutations in CheZ, R54C and V166G, that are unusual in that they cause cells to have a smooth swimming bias. These mutations were isolated as second-site suppressors of mutations in the switch complex responsible for regulating the direction of flagellar rotation (Yamaguchi, S., Aizawa, S.-I., Kihara, M. Isomura, M., Jones, C.J. and Macnab, R.M. (1986) J. Bacteriol. 168, 1172-1179). When produced at low levels in a delta cheZ host strain, CheZ R54C and CheZ V166G supported chemotaxis. However, when moderately overproduced they markedly inhibited chemotactic ability. In vitro studies revealed that these mutations enhanced the ability of CheZ to accelerate dephosphorylation of CheY. These results are discussed in relation to the possible roles and interactions of CheZ in the chemotaxis system.

UI	MeSH Term	Description	Entries
D008565	Membrane Proteins	Proteins which are found in membranes including cellular and intracellular membranes. They consist of two types, peripheral and integral proteins. They include most membrane-associated enzymes, antigenic proteins, transport proteins, and drug, hormone, and lectin receptors.	Cell Membrane Protein,Cell Membrane Proteins,Cell Surface Protein,Cell Surface Proteins,Integral Membrane Proteins,Membrane-Associated Protein,Surface Protein,Surface Proteins,Integral Membrane Protein,Membrane Protein,Membrane-Associated Proteins,Membrane Associated Protein,Membrane Associated Proteins,Membrane Protein, Cell,Membrane Protein, Integral,Membrane Proteins, Integral,Protein, Cell Membrane,Protein, Cell Surface,Protein, Integral Membrane,Protein, Membrane,Protein, Membrane-Associated,Protein, Surface,Proteins, Cell Membrane,Proteins, Cell Surface,Proteins, Integral Membrane,Proteins, Membrane,Proteins, Membrane-Associated,Proteins, Surface,Surface Protein, Cell
D008969	Molecular Sequence Data	Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.	Sequence Data, Molecular,Molecular Sequencing Data,Data, Molecular Sequence,Data, Molecular Sequencing,Sequencing Data, Molecular
D009154	Mutation	Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.	Mutations
D010766	Phosphorylation	The introduction of a phosphoryl group into a compound through the formation of an ester bond between the compound and a phosphorus moiety.	Phosphorylations
D002633	Chemotaxis	The movement of cells or organisms toward or away from a substance in response to its concentration gradient.	Haptotaxis
D003001	Cloning, Molecular	The insertion of recombinant DNA molecules from prokaryotic and/or eukaryotic sources into a replicating vehicle, such as a plasmid or virus vector, and the introduction of the resultant hybrid molecules into recipient cells without altering the viability of those cells.	Molecular Cloning
D004926	Escherichia coli	A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.	Alkalescens-Dispar Group,Bacillus coli,Bacterium coli,Bacterium coli commune,Diffusely Adherent Escherichia coli,E coli,EAggEC,Enteroaggregative Escherichia coli,Enterococcus coli,Diffusely Adherent E. coli,Enteroaggregative E. coli,Enteroinvasive E. coli,Enteroinvasive Escherichia coli
D000072236	Methyl-Accepting Chemotaxis Proteins	Transmembrane sensor receptor proteins that are central components of the chemotactic systems of a number of motile bacterial species which include ESCHERICHIA COLI and SALMONELLA TYPHIMURIUM. Methyl-accepting chemotaxis proteins derive their name from a sensory adaptation process which involves methylation at several glutamyl residues in their cytoplasmic domain. Methyl-accepting chemotaxis proteins trigger chemotactic responses across spatial chemical gradients, causing organisms to move either toward favorable stimuli or away from toxic ones.	Methyl-Accepting Chemotaxis Protein,MACP-I,MACP-II,Methyl Accepting Chemotaxis Protein 1,Methyl Accepting Chemotaxis Protein 2,Methyl Accepting Chemotaxis Protein 3,Methyl-Accepting Chemotaxis Protein I,Methyl-Accepting Chemotaxis Protein II,Methyl-Accepting Chemotaxis Protein III,Chemotaxis Protein, Methyl-Accepting,Chemotaxis Proteins, Methyl-Accepting,Methyl Accepting Chemotaxis Protein,Methyl Accepting Chemotaxis Protein I,Methyl Accepting Chemotaxis Protein II,Methyl Accepting Chemotaxis Protein III,Methyl Accepting Chemotaxis Proteins,Protein, Methyl-Accepting Chemotaxis,Proteins, Methyl-Accepting Chemotaxis
D000483	Alleles	Variant forms of the same gene, occupying the same locus on homologous CHROMOSOMES, and governing the variants in production of the same gene product.	Allelomorphs,Allele,Allelomorph
D000595	Amino Acid Sequence	The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.	Protein Structure, Primary,Amino Acid Sequences,Sequence, Amino Acid,Sequences, Amino Acid,Primary Protein Structure,Primary Protein Structures,Protein Structures, Primary,Structure, Primary Protein,Structures, Primary Protein