Biomaterial Database

Effects of phosphorylation, Mg2+, and conformation of the chemotaxis protein CheY on its binding to the flagellar switch protein FliM. 1994

M Welch, and K Oosawa, and S I Aizawa, and M Eisenbach

Department of Membrane Research and Biophysics, Weizmann Institute of Science, Rehovot, Israel.

CheY is the response regulator of bacterial chemotaxis. Previously, we showed that CheY binds to the flagellar switch protein FliM and that this binding is increased upon phosphorylation of CheY [Welch, M., Oosawa, K., Aizawa, S.-I., & Eisenbach, M. (1993) Proc. Natl. Acad. Sci. U.S.A. 90, 8787-8791]. Here, we demonstrate that it is the phosphorylated conformation of CheY, rather than the phosphate group itself, that is recognized and bound by FliM. We found that subsequent to the phosphorylation of CheY, Mg2+ was not required for the binding of CheY to FliM. However, phosphorylation of CheY did cause a change in the coordination properties of Mg2+ in the acid pocket of the protein. This change in the coordination of Mg2+ required the presence of the absolutely conserved residue Lys109. When Lys109 was substituted by arginine, the resulting CheY protein was unable to adopt an active conformation upon phosphorylation, and the protein was not bound by FliM. Surprisingly, the CheY13DK mutant protein, which is active in vivo but cannot be phosphorylated in vitro, exhibited only a low level of FliM binding activity, suggesting that its ability to cause clockwise rotation in the cell is not due to a constitutively high level of FliM binding. On the basis of these findings, we propose a mechanism for CheY activation by phosphorylation.

UI	MeSH Term	Description	Entries
D008274	Magnesium	A metallic element that has the atomic symbol Mg, atomic number 12, and atomic weight 24.31. It is important for the activity of many enzymes, especially those involved in OXIDATIVE PHOSPHORYLATION.
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
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
D011485	Protein Binding	The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.	Plasma Protein Binding Capacity,Binding, Protein
D011487	Protein Conformation	The characteristic 3-dimensional shape of a protein, including the secondary, supersecondary (motifs), tertiary (domains) and quaternary structure of the peptide chain. PROTEIN STRUCTURE, QUATERNARY describes the conformation assumed by multimeric proteins (aggregates of more than one polypeptide chain).	Conformation, Protein,Conformations, Protein,Protein Conformations
D002633	Chemotaxis	The movement of cells or organisms toward or away from a substance in response to its concentration gradient.	Haptotaxis
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
D005407	Flagella	A whiplike motility appendage present on the surface cells. Prokaryote flagella are composed of a protein called FLAGELLIN. Bacteria can have a single flagellum, a tuft at one pole, or multiple flagella covering the entire surface. In eukaryotes, flagella are threadlike protoplasmic extensions used to propel flagellates and sperm. Flagella have the same basic structure as CILIA but are longer in proportion to the cell bearing them and present in much smaller numbers. (From King & Stansfield, A Dictionary of Genetics, 4th ed)	Flagellum
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
D001426	Bacterial Proteins	Proteins found in any species of bacterium.	Bacterial Gene Products,Bacterial Gene Proteins,Gene Products, Bacterial,Bacterial Gene Product,Bacterial Gene Protein,Bacterial Protein,Gene Product, Bacterial,Gene Protein, Bacterial,Gene Proteins, Bacterial,Protein, Bacterial,Proteins, Bacterial