Table 1

Major families of one-component signal transduction systems

One-component systemDefining featuresReference(s)
AraC/XlySInvolved in regulating pathways for the catabolism of various sugars, primarily transcriptional activators, C-terminal DNA-binding domain196
ArgRInvolved in regulating amino acid metabolism, typically function as transcriptional repressors, N-terminal DNA-binding domain197
ArsR/SmtBInvolved in regulating metal homeostasis, primarily transcriptional repressors, DNA-binding domain located near the center of the protein198
AsnC/LrpInvolved in regulating amino acid metabolism, function as both transcriptional activators and repressors, N-terminal DNA-binding domain199
Crp/FnrInvolved in regulating many cellular processes, may function as activators and repressors, C-terminal DNA-binding domain200
DeoRInvolved in regulating sugar metabolism, typically function as repressors, N-terminal DNA-binding domain201
DtxRInvolved in regulating metal homeostasis, primarily transcriptional repressors, N-terminal DNA-binding domain202
FurInvolved in regulating metal homeostasis, primarily transcriptional repressors, N-terminal DNA-binding domain202
GntRInvolved in regulating numerous cellular processes, typically function as transcriptional repressors, N-terminal DNA-binding domain203
IclRInvolved in regulating carbon metabolism, function as both transcriptional activators and repressors, N-terminal DNA-binding domain204
LacIInvolved in regulating carbon metabolism, typically function as transcriptional repressors, N-terminal DNA-binding domain205
LuxRInvolved in regulating quorum sensing, typically function as activators, C-terminal DNA-binding domain206
LysRInvolved in regulating many cellular processes, function as both activators and repressors, N-terminal DNA-binding domain207
MarRInvolved in regulating antibiotic resistance, typically function as transcriptional repressors, DNA-binding domain located near the center of the protein208
MerRInvolved in regulating metal homeostasis, typically function as transcriptional repressors, N-terminal DNA-binding domain209
MetJInvolved in regulating many cellular processes, typically function as transcriptional repressors, N-terminal DNA-binding domain3
ModEInvolved in regulating metal homeostasis, function as both transcriptional activators and repressors, N-terminal DNA-binding domain210
PadRPoorly characterized family, N-terminal DNA-binding domain211
TetRInvolved in regulating antibiotic resistance, typically function as repressors, N-terminal DNA-binding domain14
XreInvolved in regulating various cellular processes, typically function as transcriptional repressors, N-terminal DNA-binding domain212, 213