Has been described for a number of bacterial species (for a review, see reference 7). In the case of S. pyogenes, the secreted streptococcal cysteine protease SpeB was found to cleave HK directly (8). In addition, the surface-bound M protein, one of the classical virulence determinants of GAS, has been demonstrated to bind HK, followed by bradykinin generation (9, 10). Binding and assembly of cont