TABLE 1.
Functions of the 17 pneumococcal proteins
| Pneumococcal virulence protein | Main role |
|---|---|
| BVH-3 (PhtE) | Pneumococcal histidine triad; possibly a role in complement inhibition |
| PspC (CbpA) | Binds to human secretory component on a polymeric Ig receptor during the first stage of translocation across the epithelium |
| PdbD | Double mutant of PLY |
| Enolase (Eno) | Binds to plasminogen, which is subsequently activated to the serine protease plasmin by tissue or urokinase plasminogen activator |
| Hyaluronidase (Hyl) | Breaks down hyaluronan-containing extracellular matrix components |
| IgA-1protease | Cleaves human IgA1 |
| NanA | Removes sialic acids and cleaves terminal sugars from various glycoconjugates, which might reveal receptors for adherence |
| PLY | Pneumolysin; cytolytic toxin that also activates complement; an important determinant of virulence in in vivo models of disease; wide range of effects on host immune components at sublytic concentrations |
| PpmA | Induces opsonophagocytosis in vitro |
| PsaA | Component of the ABC transport system, which is involved in resistance to oxidative stress and transport of Mn2+ |
| PspA | Prevents binding of C3 onto pneumococcal surface; also binds lactoferrin |
| SlrA | Cyclophilin-type PPiase can catalyze the cis-trans isomerization of proline-containing tetrapeptides; modulates the biological function of important virulence proteins |
| SP0189 | Hypothetical protein |
| SP0376 | Response regulator (intracellular location) |
| SP1003 (BVH-11-2/PhtD) | PhtD (histidine triad protein) |
| SP1633 | Response regulator (intracellular location) |
| SP1651 | Thiol peroxidase (intracellular location) |