The YqhC transcriptional activator directly binds to the promoter region of the yqhD gene, which contains the SoxS-like binding sequence as well as a 24-bp palindrome . YqhC also regulates dkgA expression . The yqhD and dkgA genes encode NADPH-dependent oxidoreductases, and both are involved in furfural reduction .
YqhC belongs to the AraC/XylS transcriptional activator family, as it shows 13.6% amino acid identity with AraC [1, 2]. The identity of the intracellular signal for YqhC is yet to be discovered . Closely related bacteria contain yqhC, yqhD, and dkgA orthologs in the same arrangement as in Escherichia coli LY180. On the other hand, orthologs of yqhC are also present in more distantly related Gram-negative bacteria .
It is probable that YqhC regulates its own expression, since it is inducible by furfural [2, 3].
Diverse aldehydes induce the yqhC-dependent expression of yqhD and dkgA genes . However, it is probable that YqhC does not interact directly with inducers but responds to a physiological effect of aldehydes .
|Connectivity class:||Local Regulator|
|Length:||957 bp / 318 aa|
|TU(s) encoding the TF:||
|Regulated gene(s)||dkgA, yqhD|
|Multifun term(s) of regulated gene(s)||
MultiFun Term (List of genes associated to the multifun term)
carbon compounds (1)
methylglyoxal metabolism (1)
|First gene in the operon(s)||yqhD|
|Simple and complex regulons|
|Simple and complex regulatory phrases||
Regulatory phrase (List of promoters regulated by the phrase)
|Functional conformation||Function||Promoter||Sigma factor||Central Rel-Pos||Distance to first Gene||Genes||Sequence||LeftPos||RightPos||Evidence (Confirmed, Strong, Weak)||References|
|3155217||3155240||[BPP], [GEA], [SM]||, |
|3155238||3155261||[GEA], [SM]||, |
|Evolutionary conservation of regulatory elements|
 Lee C., Kim I., Lee J., Lee KL., Min B., Park C., 2010, Transcriptional activation of the aldehyde reductase YqhD by YqhC and its implication in glyoxal metabolism of Escherichia coli K-12., J Bacteriol. 192(16):4205-14
 Turner PC., Miller EN., Jarboe LR., Baggett CL., Shanmugam KT., Ingram LO., 2011, YqhC regulates transcription of the adjacent Escherichia coli genes yqhD and dkgA that are involved in furfural tolerance., J Ind Microbiol Biotechnol. 38(3):431-9
 Miller EN., Jarboe LR., Yomano LP., York SW., Shanmugam KT., Ingram LO., 2009, Silencing of NADPH-dependent oxidoreductase genes (yqhD and dkgA) in furfural-resistant ethanologenic Escherichia coli., Appl Environ Microbiol. 75(13):4315-23