Table 2. The Vβ specificities and binding preferences of the GAS SAgs.
| SAg | MHC II chain bound | Zinc binding | Vβ specificity |
|---|---|---|---|
| SpeA | α | Y | 2.1, 12.2, 14.1, 15.1 |
| SpeC | β | Y | 2.1, 3.2, 12.5, 15.1 |
| SpeG* | β | Y | 2.1, 4.1, 6.9, 9.1, 12.3 |
| SpeH | β | Y | 2.1, 7.3, 9.1, 23.1 |
| SpeI | β | Y | 6.9, 9.1, 18.1, 22 |
| SpeJ* | β | Y | 2.1 |
| SpeK/L | β | Y | 1.1, 5.1, 23.1 |
| SpeL/M | β | Y | 1.1, 5.1, 23.1 |
| SpeM | ? | Y | 1.1, 5.1, 23.1 |
| SSA | α | N | 1.1, 3, 15 |
| SMEZ-1* | β | Y | 2.1, 4.1, 7.3, 8.1 |
| SMEZ-2* | β | Y | 4.1, 8.1 |
*SMEZ and SpeG are chromosomally encoded and encoded ubiquitously within the GAS metagenome. SpeJ is also chromosomally encoded; however, speJ negative clones of GAS are extremely common. While SpeB and SpeF were initially identified as SAgs, they have since been reclassified as a cysteine protease and a DNase (DNaseB) respectively. Table adapted from reference 59.