HrcA is found to negatively regulate the transcription of heat shock genes [1,2]. HrcA contains an amino terminal helix-turn-helix domain, however this corresponds to the carboxy terminal domain.

1: hrcA, the first gene of the Bacillus subtilis dnaK operon encodes a negative regulator of class I heat shock genes. Schulz A, Schumann W; J Bacteriol 1996;178:1088-1093. PMID:8576042

2: Identification of a Caulobacter crescentus operon encoding hrcA, involved in negatively regulating heat-inducible transcription, and the chaperone gene grpE. Roberts RC, Toochinda C, Avedissian M, Baldini RL, Gomes SL, Shapiro L; J Bacteriol 1996;178:1829-1841. PMID:8606155