The DNA Polymerase alpha zinc finger domain adopts an alpha-helix-like structure, followed by three turns, all of which involve proline. The resulting motif is a helix-turn-helix motif, in contrast to other zinc finger domains, which show anti-parallel sheet and helix conformation. Zinc binding occurs due to the presence of four cysteine residues positioned to bind the metal centre in a tetrahedral coordination geometry. Function of this domain is uncertain: it has been proposed that the zinc finger motif may be an essential part of the DNA binding domain [1].

1: Nuclear magnetic resonance structures of the zinc finger domain of human DNA polymerase-alpha. Evanics F, Maurmann L, Yang WW, Bose RN; Biochim Biophys Acta. 2003;1651:163-171. PMID:14499601