Comparative DMSO reductase activity of native and C-ter His-tagged YedY. Non-denaturing PAGE of periplasmic extracts (25 μg) from R. sphaeroides f. sp. denitrificans WT (lane 1), yedY- mutant (lane 2), dmsA- mutant (lane 3) and dmsA- mutant harboring the pSM88 plasmid (lane 4). (A) The gel was stained with dithionite-reduced benzyl viologen and DMSO as substrate; (B) Western blot with anti-histidine peroxidase conjugate antibodies; (C) A partial 2D PAGE from periplasmic extract of dmsA- mutant harboring the pSM88 plasmid, showing spots of native and C-ter tagged YedY (see Additional file 1 for details). MW: molecular weight standards.