FIG. 1.

(A) Table summarizing results of agar overlay assays with deletion mutants of the blp locus. Plus signs designate definite zones of inhibition, and empty cells designate combinations that were not tested. (B) Alignment of BlpM and BlpN amino acid sequences from type 6A and TIGR4 strains and the chimeric proteins from 6AblpMNO^TIGR. Shaded amino acids are nonconserved, and arrows designate putative cleavage sites of preproteins. (C) Photographs of results of selected overlay assays. Pictures a to g demonstrate test strains with zones of inhibition, while pictures h to m demonstrate test strains lacking inhibition. Pictures a and b are shown with a TIGR4 overlay, and pictures c to m are shown with an overlay of 6AΔblpMNO. Test strains: a and c, type 6A; b and f, type 19A; d, 6AblpMNO^WT; e, 6AΔblpO; g, 19AblpMNO^WT; h, 6AΔblpMNO; i, 6AΔblpM; j, 6AΔblpN; k, TIGR4; l, 6AblpMNO^TIGR4; m, 19AΔblpMNO.