1.14.13.81 iron reconstitution step with ferrous ammonium sulphate to increase the occupancy of the iron-binding sites, the purified single-subunit O2-dependent cyclase AcsF activity is reconstituted using a tricomponent electron transfer system consisting of NADPH, ferredoxin (Fd) and Fd:NADP+ reductase (FNR) 765462 1.14.13.81 reconstitution of the enzyme system from a high-speed supernatant and a membrane pellet 636333