What are Finger and Ph?

A zinc finger is a protein domain that can bind to DNA. A zinc finger consists of two antiparallel β strands, and an α helix. The zinc ion is crucial for the stability of this domain type - in absence of the metal ion the domain unfolds as it is too small to have a hydrophobic core. One very well explored sub-set of zinc-fingers (the C2H2 class) comprises a pair of cysteine residues in the beta sheets and two histidine residues in the alpha helix which are responsible for binding a zinc ion. The two other classes of zinc finger proteins are the C4 and C6 classes.