DRE-antagonist modulator (DREM)
entry list
alignment
The downstream regulatory element (DRE) is known to silence
transcription of the prodynorphin and c-fos genes. DRE-antagonistist
modulator (DREAM) binds to DRE in the apo-form, probably as a
homotetramer. "Upon stimulation by Ca2+, DREAM's ability to bind to
the DRE and its repressor function are prevented." [24]. DREM is 284
residues long and contains four EF-hands. The 110 residues preceding
the first EF-hand may be responsible for binding to DNA; however, no
homolog is recognized. The first and second EF-hands have unusual
distributions of potential Ca2+ binding ligands - X, Y, Z, -X, -Z Asn,
Cys, Thr, Asp, Thr and Asp, Asp, Asn, His, Asp. In proteins Ca2+ is
usually coordinated by O; the S of Cys and the N of His may coordinate
water which in turn binds Ca2+. The third and fourth EF-hands appear
to bind calcium.