Super-activator variants of the cyanobacterial transcriptional regulator ChlR essential for tetrapyrrole biosynthesis under low oxygen conditions

ChlR is a MarR-type transcriptional regulator that activates the transcription of the chlAII-ho2-hemN operon in response to low oxygen conditions in the cyanobacterium Synechocystis sp. PCC 6803. Upon exposure to low oxygen conditions, ChlR activates transcription of the operon that encodes enzymes critical to tetrapyrrole biosynthesis under low oxygen conditions. We previously identified a super-activator variant, D35H, of ChlR that...