| Types | DnaRegion
|
| Roles | promoter
Regulatory
|
| Sequences | BBa_M36802_sequence (Version 1)
|
Description
The alcR operator/promoter provides a binding site for the alcR protein-acetaldehyde complex. In Aspergillus nidulans, the alcR gene encodes a regulatory protein which activates the expression of the ethanol utilization (alc) pathway if the co-inducer acetaldehyde is present. Ethanol is converted to acetaldehyde by the alcohol dehydrogenase and further metabolized to acetate by the aldehyde dehydrogenase. Both genes alcA and aldA are regulated by AlcR. AlcR also regulates its own expression by autoactivation. The AlcR DNA binding domain contains a zinc bi-nuclear cluster, which can bind either to symmetric and asymmetric sites with same affinity. In contrast to other members of the Zn2Cys6, the DNA binding domain is stretch of 16 amino acid residues between the third and fourth cysteine. AlcR binds as a monomer, but 2 proteins can bind to inverted repeats in a noncooperative manner. Additional DNA sequences upstream of the zinc cluster were identified to be responsible for high-affinity binding,
Notes
The mechanism by which the complex binds and inhibits/activates this region is currently unknown.
Source
This concept comes from the 2011 iGEM ETH Zurich team. (http://2011.igem.org/Team:ETH_Zurich). It also comes from extensive research done by Beatrice Felenbok. The sequence is the highest affinity binding site for alcR-acetaldehyde complex. (http://www.ncbi.nlm.nih.gov/pmc/articles/PMC364357/pdf/molcellb00027-0040.pdf)
