Controls the expression of the cellular protein quality control genes clpC, clpE and clpP, as well as mcsA and mcsB, by acting as a repressor of these class III stress genes. After heat shock, CtsR is degraded by the ClpCP and ClpEP proteolytic systems, ensuring the derepression of clpE, clpP and the clpC operon. CtsR negatively autoregulates its own synthesis (By similarity). Repressor activity is controlled via phosphorylation on arginine residues. Unphosphorylated CtsR binds with high affinity to its DNA consensus site and inhibits transcription of downstream genes, whereas the McsB-phosphorylated CtsR repressor is not able to bind to DNA, thus allowing heat-shock gene expression (PubMed:19498169). Homodimer. CtsR autoinduces its own synthesis by derepression of the clpC operon after heat shock. Is composed of two distinct domains: an N-terminal DNA binding domain that adopts the winged HTH fold (residues 2-72) and a C-terminal dimerization domain (residues 79-153) that consists of four alpha helices organized in a four-helix bundle. Phosphorylated on Arg-28, Arg-49 and Arg-62 by McsB. Belongs to the CtsR family.