SDS-PAGE analysis of recombinant HutZ and rFur. A Whole-cell proteins were prepared from E. coli BL21(DE3)/pEtHutZ cultured in LB medium before (lane 1) and after (lane 2) IPTG induction. Lane 3, recombinant SoFer1 after purification by affinity chromatography. B Western immunoblot analysis of purified rHutZ. C Expression and purification of rFur.