RegulonDB RegulonDB 10.6.3: Operon Form
   

acrEF operon and associated TUs in Escherichia coli K-12 genome




Operon      
Name: acrEF
This page displays every known transcription unit of this operon and their known regulation.


Transcription unit          
Name: acrEF
Gene(s): acrE, acrF   Genome Browser M3D Gene expression COLOMBOS
Note(s): During an experiment using increasing concentrations of tetracycline, the transcription of the acrEF operon was induced in low concentrations (1.5 and 4 mg/L), but this induction decreases in high concentrations (10 mg/L) |CITS:[17426813]|. acrE expression is increased at least 5-fold by indole |CITS: [15686558]|.
EnvR functions as a switch for the expression of acrAB and acrEF. It is not known which compound and/or condition induces the expression of EnvR |CITS:[18567659]|.
A probable repression effect on the transcription of the operon acrEF has been assigned to the EnvR protein |CITS:[15608167]|. However, it was demonstrated that EnvR is not the effective repressor of acrEF |CITS:[18567659]|.
Evidence: [BTEI] Boundaries of transcription experimentally identified
[LTED] Length of transcript experimentally determined
[LTED] Length of transcript experimentally determined
Reference(s): [1] Klein JR., et al., 1991
Promoter
Name: acrEp
+1: 3413702
Sigma Factor: Sigma70 Sigmulon
Distance from start of the gene: 162
Sequence: ttacgaggttttaattctgcctctttcaacccgcgtcaaaataaaacagtagaatattaaTctttttttgtgtttatgtgc
                        -35                       -10       +1                   
Evidence: [AIPP]
Reference(s): [2] Huerta AM., et al., 2003
Terminator(s)
Type: rho-independent
Sequence: gataaatcagAAACATAAAGGCGCTTTCGGGTGCCTTTATTATTTccagtgaaac
Note(s): The terminator sequence downstream of acrF gene appears to form a weak stem-loop (?G= -11.4 kcal/mol) Klein JR,1991
Reference(s): [1] Klein JR., et al., 1991
TF binding sites (TFBSs)
Type Transcription factor Function Promoter Binding Sites Growth Conditions Evidence (Confirmed, Strong, Weak) Reference(s)
LeftPos RightPos Central Rel-Pos Sequence
nd FNR1 activator acrEp nd nd nd nd nd [AIBSCS], [GEA] [3]
Type Transcription factor Function Promoter Binding Sites Growth Conditions Evidence (Confirmed, Strong, Weak) Reference(s)
LeftPos RightPos Central Rel-Pos Sequence
nd H-NS repressor acrEp nd nd nd nd nd [GEA] [4]
Note(s): 1By making use of microarray analyses it was concluded that FNR activates acrEF operon expression under anaerobiosis. A putative FNR-binding site, which was not reported in the paper, was identified upstream of this operon Salmon K,2003.1By making use of microarray analyses it was concluded that FNR activates acrEF operon expression under anaerobiosis. A putative FNR-binding site, which was not reported in the paper, was identified upstream of this operon Salmon K,2003.





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