Premium
Dissection of the sensor domain of the copper‐responsive histidine kinase CorS from Myxococcus xanthus
Author(s) -
SánchezSutil María Celestina,
MarcosTorres Francisco Javier,
Pérez Juana,
RuizGonzález María,
GarcíaBravo Elena,
MartínezCayuela Marina,
GómezSantos Nuria,
MoraledaMuñoz Aurelio,
MuñozDorado José
Publication year - 2016
Publication title -
environmental microbiology reports
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.229
H-Index - 69
ISSN - 1758-2229
DOI - 10.1111/1758-2229.12389
Subject(s) - myxococcus xanthus , histidine kinase , multicopper oxidase , periplasmic space , histidine , signal peptide , mutant , biochemistry , copper , chemistry , mutagenesis , two component regulatory system , biology , biophysics , peptide sequence , microbiology and biotechnology , gene , escherichia coli , amino acid , enzyme , laccase , organic chemistry
Summary Myxococcus xanthus CorSR is a two‐component system responsible for maintaining the response of this bacterium to copper. In the presence of this metal it upregulates, among others, the genes encoding the multicopper oxidase CuoA and the P 1B ‐ATPase CopA. Dissection of the periplasmic sensor domain of the histidine kinase CorS by the analysis of a series of in‐frame deletion mutants generated in this portion of the protein has revealed that copper sensing requires a region of 28 residues in the N terminus and another region of nine residues in the C terminus. Point mutations at His34, His38 and His171 demonstrate that they are essential for the ability of CorS to sense copper. Furthermore, the use of a bacterial two‐hybrid system has revealed dimerization between monomers of CorS even in the absence of any metal, and that copper enhances this interaction. When dimerization was tested with proteins mutated at the three essential His residues, it was observed that these proteins maintain the intrinsic dimerization ability in the absence of metal. In contrast to the wild‐type protein, copper did not strengthen the interaction, corroborating that copper binding to the three His residues of CorS is required for enhancing dimerization and transmitting the signal.