Equal amounts of inner membrane protein fractions prepared from purified spores of the wild type, ylyA mutant, and ylyA overexpression strains were subjected to SDS-PAGE and Western blot analysis. Western membranes were probed with antibodies against GerAA, GerAC, GerBC, GerKA, SpoVAD and GerD. For direct comparison, dilutions of samples prepared from wild type and ylyA mutant (A) or wild type and ylyA overexpression (B) spores were run on the same gel.