FIG. 1.
Purification of CII protein. (A) Wild-type CII (10 μg), His6-CII (5 μg), and CII-His6 (5 μg) were resolved by SDS-PAGE and stained with Coomassie brilliant blue. Wild-type CII carries 3 additional residues, GSH, at the N terminus (Mw, 11,337); His6-CII carries 20 additional residues, MGSSHHHHHHSSGLVPRGSH, at the N terminus (Mw, 13,219) and CII-His6 carries 12 additional residues, EFIEGRHHHHHH. at the C terminus (Mw, 12,610). (B) Analysis of FtsH protease activity, its dependence on ATP, and the effect of inhibitors. Reactions were carried under standard conditions for 60 min. Lane 1, CII alone; lane 2, reaction in the absence of ATP; lane 3, complete reaction; lane 4, reaction in the presence of 10 mM o-phenanthroline; lane 5, reaction in the presence of the inhibitor mix Complete (Boehringer Mannheim).