Table 2.

List of some TCS bacterial histidine kinases and their main functions

TCS histidine kinase in Bacteria	Functions
PhoQ 145,146	Adaptation to acidic and low Mg2+ environments
DcuS 147	Stimulated by the presence of C4-dicarboxylates such as fumarate, succinate, malate, and tartrate
DosS 148, DosT 149	Detect O2, CO and NO
CitA 147	Detects presence of citrate
AbsF 147	Arabinofuranosidase sensor protein and complex carbohydrate sensor
AgrC 150	Autoinducing peptide (AIP) sensor to coordinate quorum sensing due to virulence factors
PhoR 147	Phosphate regulon sensor kinase
LuxQ 147	Cell density sensor kinase which acts as an “apostate” phosphatase by inactivation of its autophosphorylation in presence of Autoinducer-2 (AI-2)
DctB 147	Involved in the transport of C4-dicarboxylates
ComD 151	Competence stimulating peptide sensor
KinD 147	Phosphorylates the sporulation-regulatory protein Spo0F
HK29s 147	Uncharacterized periplasmic histidine kinase sensor domain
NarX 147	Sensor for nitrate/nitrite
VanS 152	Vancomycin receptor
Tar 147	Two aspartate binding receptor
TorS 147	Detects trimethylamine-N-oxide (TMAO) in anaerobic utilization
FixL 153	Oxygen sensor
TodS 154	Control the expression of the toluene dioxygenase pathway
RetS 147	Regulator of Exopolysaccharide and Type III Secretion
CpxA 155	Responds to envelope stress response
EnvZ 156	Osmolarity sensor
CheA 135	Transmit signals from chemoreceptors