RegulonDB RegulonDB 10.8:Regulon Page

CRP-Sxy DNA-binding transcriptional activator

Synonyms: CRP-Sxy
CRP appears to interact with the Sxy protein to regulate some genes related to DNA uptake (natural competence). The residues Q194 and L196, located in the named Sxy Interacting Region (SIR) and close to the DNA-binding region in CRP, appear to be involved in the CRP-Sxy interaction [1]. The CRP-Sxy complex recognized a DNA-binding site that has an asymmetric organization: it has two distinct half sites, one of which is similar to the canonical CRP DNA-binding site, but the other half site is less conserved [1]. In E. coli [] and in some other bacteria, the putative regulon CRP-Sxy has been identified through microarray analysis [3].

Transcription factor      
TF conformation(s):
Name Conformation Type TF-Effector Interaction Type Apo/Holo Conformation Evidence (Confirmed, Strong, Weak) References
CRP-Sxy Functional   [IMP] [1]
Evolutionary Family: CRP
Connectivity class: Local Regulator
Gene name: crp
  Genome position: 3486120-3486752
  Length: 633 bp / 210 aa
Operon name: crp
TU(s) encoding the TF:
Transcription unit        Promoter
Gene name: sxy
  Genome position: 1021138-1021767
  Length: 630 bp / 209 aa
Operon name: sxy
TU(s) encoding the TF:
Transcription unit        Promoter

Regulated gene(s) sxy
Multifun term(s) of regulated gene(s)
activator (1)
Regulated operon(s) sxy
First gene in the operon(s) sxy
Simple and complex regulons CRP-Sxy
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
  CRP-Sxy activator sxyp Sigma70 -81.5 -136.5 sxy
1020991 1021013 [APIORCISFBSCS], [CV(GEA)], [GEA] [1], [2]

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


 [IMP] Inferred from mutant phenotype

 [APIORCISFBSCS] A person inferred or reviewed a computer inference of sequence function based on similarity to a consensus sequence.

 [CV(GEA)] cross validation(GEA)

 [GEA] Gene expression analysis


 [1] Sondberg E., Sinha AK., Gerdes K., Semsey S., 2019, CRP Interacts Specifically With Sxy to Activate Transcription in Escherichia coli., Front Microbiol 10:2053

 [2] Jaskolska M., Gerdes K., 2015, CRP-dependent positive autoregulation and proteolytic degradation regulate competence activator Sxy of Escherichia coli., Mol Microbiol 95(5):833-45

 [3] Cameron AD., Redfield RJ., 2006, Non-canonical CRP sites control competence regulons in Escherichia coli and many other gamma-proteobacteria., Nucleic Acids Res 34(20):6001-14