RegulonDB RegulonDB 10.10:Regulon Page

LldR DNA-binding transcriptional dual regulator

Synonyms: LldR-(S)-lactate, LldR
LldR, formerly named "lactate regulator", is a transcription factor that controls expression of genes involved in transport and catabolism of L-lactate [1, 3]. This regulator has a dual function and is positively and negatively autoregulated. In the absence of L-lactate and under anaerobic conditions, this regulator repressed the transcription of the lldPRD operon [1]. In this repression system, LldR binds to two operators and probably leads to repressor DNA looping [1]. Expression of this regulator is also stimulated in presence of L-lactate, and this inductor promotes a conformational change that probably destabilizes the DNA loop, promoting the transcription open complex [1]. On the another hand, the transcription of lldR is also induced upon biofilm formation compared to planktonic growth in both exponential and stationary phases. An lctR mutant is impaired in biofilm formation [4].
Read more >

Transcription factor      
TF conformation(s):
Name Conformation Type TF-Effector Interaction Type Apo/Holo Conformation Evidence (Confirmed, Strong, Weak) References
LldR Functional   Apo [BPP], [GEA], [IPI], [SM] [1]
LldR-(S)-lactate Functional Allosteric Holo [BPP], [GEA], [IPI], [SM] [1]
Evolutionary Family: GntR
Sensing class: Sensing external and internal signals
Connectivity class: Local Regulator
Gene name: lldR
  Genome position: 3779054-3779830
  Length: 777 bp / 258 aa
Operon name: lldPRD
TU(s) encoding the TF:
Transcription unit        Promoter

Regulated gene(s) lldD, lldP, lldR
Multifun term(s) of regulated gene(s) MultiFun Term (List of genes associated to the multifun term)
aerobic respiration (2)
anaerobic respiration (1)
electron donors (1)
carbon compounds (1)
Porters (Uni-, Sym- and Antiporters) (1)
Read more >
Regulated operon(s) lldPRD
First gene in the operon(s) lldP
Simple and complex regulons ArcA,LldR
Simple and complex regulatory phrases Regulatory phrase (List of promoters regulated by the phrase)

Transcription factor regulation    

Transcription factor binding sites (TFBSs) arrangements

  Functional conformation Function Promoter Sigma factor Central Rel-Pos Distance to first Gene Genes Sequence LeftPos RightPos Evidence (Confirmed, Strong, Weak) References
  LldR repressor lldPp Sigma70 -97.0 -207.0 lldP, lldR, lldD
3777181 3777203 [GEA], [AIBSCS], [BPP], [SM] [1]
  LldR-(S)-lactate activator lldPp Sigma70 -97.0 -207.0 lldP, lldR, lldD
3777181 3777203 [GEA], [AIBSCS], [BPP], [SM] [1]
  LldR repressor lldPp Sigma70 30.0 -81.0 lldP, lldR, lldD
3777307 3777329 [GEA], [AIBSCS], [APIORCISFBSCS], [BPP], [SM] [1], [2]

Evolutionary conservation of regulatory elements    
     Note: Evolutionary conservation of regulatory interactions and promoters is limited to gammaproteobacteria.
Promoter-target gene evolutionary conservation