InterPro domain: IPR038256

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. The 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. It is involved in providing a structural platform for interactions with both oligonucleotide/oligosaccharide (OB) and phosphoesterase domains of the B subunit [ 1 , 2 , 3 ].

1. Nuclear magnetic resonance structures of the zinc finger domain of human DNA polymerase-alpha. Biochim. Biophys. Acta 1651, 163-71
2. Crystal structure of the human Polϵ B-subunit in complex with the C-terminal domain of the catalytic subunit. J Biol Chem 292, 15717-15730
3. 3D architecture of DNA Pol alpha reveals the functional core of multi-subunit replicative polymerases. EMBO J. 28, 1978-87