NCIt definition : Zinc-binding, DNA-binding motifs in proteins contain amino acids that are folded into
a single DNA-binding structural unit around a zinc atom.;
NCIt note : The Zinc Finger Domain is found in many proteins that bind nucleic acids, typically
DNA binding transcription factors. There are several classes of Zn finger proteins.
Some bind Zn with only Cys residues (e.g., nuclear receptor superfamily) while others
coordinate Zn with Cys and His residues. In the 25-amino acid C2H2 type motif, Zn2
is held between a pair of anti-parallel beta strands and a single alpha helix by a
pair of invariant Cys and His residues. The Cys/His type proteins generally contain
repeated units and bind DNA as a monomer, while Cys/Cys proteins contain two units
that bind inverted DNA repeats as homo- or heterodimers. In some Cys/Cys types the
Zn ion folds the involved region into a globular structure that binds DNA.;