FIG 5.

Three conserved cysteines are essential for SufR function in vivo. (A) The effects of Cys residue mutation on SufR repression of sufR promoter activities were investigated using an E. coli bioluminescence reporter system. A schematic representation of the reporter system (left) and the effect of SufR variants on bioluminescence level of E. coli containing reporter plasmid pOsufRlux (right). RLU (relative light units) represents bioluminescence level. (B) RT-qPCR analysis of the transcriptional levels of suf genes in S. avermitilis WT, DsufR, and complemented strain of DsufR using sufR or sufR variants. The strains were grown in FM-I for 2 or 6 days. Error bars, standard deviation of three technical replicates.