FIG. 6.

Complementation of RopB deletion demonstrated by protease expression. Derivatives of S. pyogenes strain HSC5 (wild type) were grown on protease indicator plates overnight at 37°C in an anaerobic environment. The strains evaluated included MNN100 (ΔropB), HSC5 with the vector alone (wild type + pLZ12), MNN100 with the vector alone (Δrop + pLZ12), MNN100 with a ropB-complementing plasmid (Δrop + pMNN23), and HSC5 with a ropB-complementing plasmid (wild type + pMNN23). Clear zones around colonies indicate protease activity.