FIG. 1.

Expression and identification of S. pyogenes SibA protein. (A) Coomassie brilliant blue-stained 10% polyacrylamide gel. Lane 1, S. pyogenes A106 whole-cell extract; lane 2, recombinant SibA purified from Escherichia coli JM109; lane 3, supernatant from S. pyogenes A106 overnight-growth culture. (B) Western blot analysis of the equivalent protein samples described for panel A using rabbit anti-SibA antiserum. Positions of molecular mass markers are shown (in kilodaltons) on the left of panel A. The 45-kDa SibA protein is indicated with a large arrow; the smaller arrows indicate smaller reactive proteins.