The human estrogen receptor is a symmetrical dimeric nuclear protein that can regulate gene expression by binding to a DNA sequence called an estrogen response element (ERE) near the promoter of its target genes. Each subunit of the receptor binds to about six base pairs of DNA. Which of the following sequences is a likely candidate for the ERE? The sequences are written in the 5′-to-3′ direction. The letter N represents any of the four DNA bases.
A) AGGTCANNNTGACCT
B) AGGTCANNNAGGTCA
C) AGGTCANNNACTGGA
D) AGGTCANNNATATAT
E) AGGCCTNNNTCATGA

Question

Quizplus · Accepted Answer

Such a symmetrical dimer is expected to recognize a corresponding symmetrical DNA sequence with inverted repeats, such that both strands have the same sequence when read in the 5′-to-3′ direction. Each subunit recognizes the sequence AGGTCA.

The Human Estrogen Receptor Is a Symmetrical Dimeric Nuclear Protein