Binding of a regulatory protein to DNA

Gene regulatory proteins can recognize DNA
sequence information without having to open
the hydrogen bonds within the helix. Each base
pair represents a distinctive pattern of hydrogen
bond donors (example shown in red) and
hydrogen acceptors (example shown in green).
These proteins recognize the major groove of
DNA, where binding takes place. Here a single
contact of an asparagine (Asn) of a gene-regulatory
protein with a DNA base adenine (A) is
shown. A typical area of surface-to-surface contact
involves 10–20 such interactions.