Secretion of SC15 is severely affected in strains transformed with the SC15 hairpin construct. (A and B) A PVDF membrane was placed underneath colonies grown on top of a PC membrane. This was followed by immunodetection for SC15 (C) and SC3 (D), respectively. The colonies on each plate are arranged in the following order: wild-type strain 4-40 (top, left), and recombinant strains S1 (top, right), S3 (bottom, left), and S5 (bottom, right).