Open AccessMcsA and the roles of metal‐binding motif in S taphylococcus aureus
Author(s) -
Sitthisak Sutthirat,
Kitti Thawatchai,
Boonyonying Kamala,
Wozniak Darren,
Mongkolsuk Skorn,
Jayaswal Radheshyam K.
Publication year - 2012
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.2011.02468.x
Subject(s) - operon , staphylococcus aureus , structural motif , biochemistry , biology , cysteine , binding site , dna binding protein , chemistry , gene , escherichia coli , bacteria , genetics , transcription factor , enzyme
McsA is a key modulator of stress response in S taphylococcus aureus that contains four CXXC potential metal‐binding motifs at the N‐terminal. S taphylococcus aureus ctsR operon encodes ctsR , clpC , and putative mcsA and mcsB genes. The expression of the ctsR operon in S . aureus was shown to be induced in response to various types of heavy metals such as copper and cadmium. McsA was cloned and overexpressed, and purified product was tested for metal‐binding activity. The protein bound to Cu(II) , Zn(II) , Co(II) , and Cd(II) . No binding with any heavy metal except copper was found when we performed site‐directed mutagenesis of Cys residues of three CXXC motifs of McsA . These data suggest that two conserved cysteine ligands provided by one CXXC motif are required to bind copper ions. In addition, using a bacterial two‐hybrid system, McsA was found to be able to bind to McsB and CtsR of S . aureus and the CXXC motif was needed for the binding. This indicates that the Cys residues in the CXXC motif are involved in metal binding and protein interaction.