Fig. 7
The prediction of promoter regions of sulVs and binding sites of ArcA (a). The − 35 and − 10 regions of the promoter PsulVs have been identified. Bold and italic part represents the ArcA binding site, predicted using both BPROM and consistent sequence of 5′- nGTTAATTAn-3′(n is A or T) in E. coli (Lynch and Lin 1996). Recombinant ArcA was purified from BL21(DE3)/pET28a-arcA (b). Lane 1, protein Marker; lane 2, proteins from un-induced BL21(DE3)/pET28a-arcA; lane 3, proteins from induced BL21(DE3)/pET28a-arcA; lane 4, purified ArcA. Specific binding of ArcA to the promoter regions of sulVs determined by EMSA (c). Lane 1, ArcA and PsulVs; lane 2, ArcA; lane 3, PsulVs. A 303 bp DNA fragment from the upstream of promoter was used as a negative control (d). Lane 1, ArcA and negative DNA control; lane 2, negative DNA; lane 3, ArcA