Transcription regulator that acts as a central regulatory node for the integration of external bacterial signals leading to the regulation of secondary metabolite gene clusters such as orsellinic, lecanoric acid, cichorine, 2,4-dihydroxy-3-methyl-6-(2-oxopropyl)benzaldehyde (dba), emericellamide or microperfuranone clusters. Expression is induced during co-cultivation with Streptomyces rapamycinicus. Results in a significantly reduced expression of orsA and orsD, and in complete loss of orsellinic acid production, during response to Streptomyces rapamycinicus.