Open AccessCloning and characterization of the Salmonella typhimurium-specific chemoreceptor Tcp for taxis to citrate and from phenol.
Author(s) -
Kimiko Yamamoto,
Yasuo Imae
Publication year - 1993
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.90.1.217
Subject(s) - chemoreceptor , biochemistry , peptide sequence , escherichia coli , chemistry , chemotaxis , biology , salmonella , bacteria , gene , receptor , genetics
Salmonella typhimurium shows an attractant response to citrate and a repellent response to phenol, and a chemoreceptor mediating these responses has been identified and named Tcp (taxis to citrate and away from phenol). Tcp is one of the methyl-accepting chemotaxis proteins that have a molecular mass of approximately 60 kDa estimated by SDS/PAGE, and its methylation level is increased by citrate and decreased by phenol. Tcp also mediates an attractant response to metal-citrate complexes. The complete nucleotide sequence of the tcp coding region has been determined. The deduced amino acid sequence of Tcp, consisting of 547-amino acid residues, is homologous with that of the aspartate chemoreceptor of S. typhimurium. Thus, Tcp is another member of the bacterial transmembrane chemoreceptor family. Because citrate is a good carbon source for S. typhimurium but is not a carbon source for the closely related species Escherichia coli and because citrate utilization is used as a key diagnostic character to distinguish these species, it is reasonable to assume that Tcp is specific to S. typhimurium.