title: Structural insight into the low affinity between Thermotoga maritima CheA and CheB compared to their Escherichia coli/Salmonella typhimurium counterparts.
abstract: CheA-mediated CheB phosphorylation and the subsequent CheB-mediated demethylation of the chemoreceptors are important steps required for the bacterial chemotactic adaptation response. Although Escherichia coli CheB has been reported to interact with CheA competitively against CheY, we have observed that Thermotoga maritima CheB has no detectable CheA-binding. By determining the CheY-like domain crystal structure of T. maritima CheB, and comparing against the T. maritima CheY and Salmonella typhimurium CheB structures, we propose that the two consecutive glutamates in the β4/α4 loop of T. maritima CheB that is absent in T. maritima CheY and in E. coli/S. typhimurium CheB may be one factor contributing to the low CheA affinity.
authors.affiliation: School of Systems Biomedical Science, College of Natural Sciences, Soongsil University, Seoul, Republic of Korea. psy@ssu.ac.kr
authors.forename: Sangyoun
authors.initials: S
authors.lastname: Park
authors.forename: Brian R
authors.initials: BR
authors.lastname: Crane
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry* / Q000378:metabolism*; D018360:Crystallography, X-Ray; D004926:Escherichia coli / Q000378:metabolism*; D029968:Escherichia coli Proteins; D000071677:Histidine Kinase; D008565:Membrane Proteins / Q000737:chemistry* / Q000378:metabolism*; D000072236:Methyl-Accepting Chemotaxis Proteins; D008958:Models, Molecular; D008969:Molecular Sequence Data; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D012486:Salmonella typhimurium / Q000378:metabolism*; D016415:Sequence Alignment; D013329:Structure-Activity Relationship; D020124:Thermotoga maritima / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D008565:Membrane Proteins; D000072236:Methyl-Accepting Chemotaxis Proteins; C000607606:cheY protein, E coli; C069656:CheB protein, Bacteria; D000071677:Histidine Kinase; C000607608:cheA protein, E coli