Fig. 5From: Mycothiol maintains the homeostasis and signalling of nitric oxide in Streptomyces coelicolor A3(2) M145Proposed model of intracellular nitric oxide (NO) homeostasis in Streptomyces coelicolor A3(2) M145. Flavohaemoglobin (Fhb) and nitrate reductase (Nar) mediate the circulation of NO, NO3−, and NO2.−. DevS/R is activated or inactivated depending on intracellular NO levels. NO directly regulates actinorhodin synthesis through the DevS/R two-component regulatory system, which modulates actII-ORF4 expression. DevR also regulates nar2 expression and NO production. Intracellular NO homeostasis is maintained through Fhb metabolism and its interaction with mycothiol (MSH) (S-nitrosylation) to form S-nitrosomycothiol (MSNO)Back to article page