Table 3.
Input domains found in Azospirillum sensing HKs
| Strains | A. lipoferum 4B | Azospirillum sp. B510 | A. brasilense Sp245 | A. brasilense CBG497 | Putative signal(s) detected | ||||
|---|---|---|---|---|---|---|---|---|---|
| HK typea | ClaHK | HyHK | ClaHK | HyHK | ClaHK | HyHK | ClaHK | HyHK | |
| Abundant input domains | |||||||||
| PAS / PAC | 43 | 42 / 1 | 35 | 35 / 3 | 46 | 71 | 35 | 71 | Small molecules, ions, gases, light, and redox state sensing |
| HAMP | 12 | 18 | 18 | 9 | 14 | 11 | 11 | 13 | Signal transduction |
| Uncommon input domains | |||||||||
| GAF | 3 | 4 | 3 | 4 | 7 | 4 | 5 | 4 | Redox or oxygen sensing; cGMP binding |
| PHY | 1 | - | 1 | 1 | 1 | 1 | 1 | 1 | Tetrapyrroles; light-sensing |
| CHASE | 3 | - | 2 | - | 3 | - | 2 | - | Small molecules recognition |
| MASE | 1 | 1 | 2 | - | 1 | - | 1 | 1 | Membrane associated sensor |
| 2CSK_N | 1 | - | 3 | - | 1 | - | 1 | - | Unknown; commonly found in N-terminal parts of HK |
| Cache | - | 4 | - | 4 | 2 | 3 | - | - | Small molecules recognition |
| MHYT | - | 2 | - | 3 | - | - | - | 2 | Putatively involved in metal sensing |
| cNMP_binding | 1 | - | 1 | - | - | - | - | - | Cyclic nucleotide monophosphate-binding |
| S_TKc | 1 | - | 1 | - | - | - | - | - | Serine/Threonine kinase catalytic domain |
| SBP_bac_1 | 1 | - | 1 | - | - | - | 1 | - | Bacterial extracellular solute binding protein |
| CheB methylesterase | - | - | 1 | 2 | - | - | - | - | Chemotaxis |
| MeTRC | - | - | 1 | 2 | - | - | - | - | Methyl transferase |
| NIT | - | - | 1 | - | - | - | - | - | Nitrate and nitrite responsive |
| PBPb | - | - | - | - | 1 | - | 1 | - | High-affinity periplasmic solute-binding protein |
a ClaHK Classic Histidine Kinase, HyHK Hybrid Histidine Kinase