Table 1. Classification of B.subtilis transcription factors (including sigma factors).
| Family |
Subfamily |
Annotated |
Predicted |
| Sigma factors | σ70 | 8 | 1 |
| σ54 | 1 | 0 | |
| σ70 ECF | 3 | 5 | |
| Helix–turn–helix family | MarR | 1 | 22 |
| LacI | 5 | 6 | |
| GntR | 3 | 18 | |
| LysR (HTH1) | 4 | 16 | |
| ArsR (HTH5) | 1 | 6 | |
| DeoR | 3 | 4 | |
| AraC/XylS (HTH2) | 1 | 11 | |
| GerE | 3 | 7 | |
| CRP | 1 | 1 | |
| Xre (HTH3) | 3 | 14 | |
| MerR | 5 | 5 | |
| TetR | 1 | 18 | |
| AsnC | 4 | 3 | |
| LexA | 1 | 0 | |
| HTH6• | 0 | 2 | |
| Other families | Trans, Reg. C | 2 | 11 |
| Response Reg. | 5 | 30 | |
| Fur | 2 | 1 | |
| σ54 binding factors | 4 | 1 | |
| Bgl antitermin. | 6 | 2 | |
| CSD | 0 | 3 | |
| IclR | 1 | 0 | |
| GreA | 0 | 1 | |
| Fe-dep. Repress. | 0 | 1 | |
| HrcA | 1 | 0 | |
| Arg repressor | 1 | 0 | |
| No families assigned | 21 | 17 | |
| Total | 91 | 206 |
Note that these classifications are based on the presence of functional domains and are not mutually exclusive.