<p>Immunoblots of lactococcal cells corresponding to the empty vector GRS1052 clone (lane 1) and those to the nisin-induced WT (GRS1189; lane 2) and SpaF pilin-deleted (GRS1126; lane 3) SpaFED-piliated clones were probed separately with polyclonal anti-SpaD (<b>A</b>), anti-SpaE (<b>B</b>), and anti-SpaF (<b>C</b>) sera as described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0113922#s4" target="_blank">Materials and Methods</a>. Apparent positioning of monomeric SpaD, SpaE, and SpaF proteins is indicated on the right of each immunoblot by an asterisk. A dense ladder-like smear of high-molecular-weight (HMW) protein bands represents the longest lengths of pili and these are indicated on the top left of the immunoblot. The positions and sizes of the molecular weight markers are shown along the left side of the immunoblot.</p
