Ji Q, Zhang L, Jones MB, Sun F, Deng X, Liang H, Cho H, Brugarolas P, Gao YN, Peterson SN, Lan L, Bae T, He C
Molecular Mechanism of Quinone Signaling Mediated Through S-quinonization of a YodB Family Repressor QsrR.
Proceedings of the National Academy of Sciences of the United States of America. 2013 Mar 11;
Quinone molecules are intracellular electron-transport carriers, as well as critical intra- and extracellular signals. However, transcriptional regulation of quinone signaling and its molecular basis are poorly understood. Here, we identify a thiol-stress-sensing regulator YodB family transcriptional regulator as a central component of quinone stress response of Staphylococcus aureus, which we have termed the quinone-sensing and response repressor (QsrR). We also identify and confirm an unprecedented quinone-sensing mechanism based on the S-quinonization of the essential residue Cys-5. Structural characterizations of the QsrR-DNA and QsrR-menadione complexes further reveal that the covalent association of menadione directly leads to the release of QsrR from operator DNA following a 10° rigid-body rotation as well as a 9-Å elongation between the dimeric subunits. The molecular level characterization of this quinone-sensing transcriptional regulator provides critical insights into quinone-mediated gene regulation in human pathogens.