TABLE 3.

Identified streptococcal proteins that contain secretion signal sequences

Function and characterization status	Extracellular proteins
Previously characterized	NAD+-glycohydrolase (SP16), streptolysin O (SP14), M1 (SP31) and M3 (SP15) protein, mitogenic factor (DNase) (SP38), streptococcal pyrogenic exotoxin A (SP26), streptococcal inhibitor of complement (SP36), streptokinase (SP41)
Homologous to protein with known function	Class B acid phosphatase (SPIX), serine protease (SP24), cyclodextrin glucosyltransferase (SP30), autolysin (SP23), SP22
Homologous to known protein but no known function	Immunogenic secreted protein homologue (SP13), L. lactis putative secreted protein (SP35)
No known homologue and no known function	SP27