Effect of NsrR on AniA protein expression in wild-type, mutant, and complemented mutant strains of M. catarrhalis. Whole-cell lysates of the strains were probed in a Western blot analysis with polyclonal AniA antiserum (A) or with the CopB-specific monoclonal antibody 10F3 (18) (B) as the primary antibody. Lane 1, wild-type strain O35E; lane 2, O35E nsrR mutant; lane 3, O35E aniA mutant; lane 4, O35E nsrR(pWW115); lane 5, O35E nsrR(pWW150); lane 6, wild-type ETSU-9; lane 7, ETSU-9 nsrR mutant; lane 8, ETSU-9 aniA mutant; lane 9, ETSU-9 nsrR(pWW115); lane 10, ETSU-9 nsrR(pWW150). The positions of the putative AniA monomers and dimers are indicated by arrows on the right in panel A. The CopB outer membrane protein was used as a loading control, and its position is indicated by an arrow on the right in panel B. The positions of molecular mass markers are indicated on the left in each panel.