Multiple alignment of the two-Zn-finger modules of eukaryotic Pol α, ζ, δ, and ε, and the single Zn-finger of archaeal PolD. The sequences are denoted by their GI numbers and species names. The positions of the first and the last residues of the aligned region in the corresponding protein are indicated for each sequence. The numbers within the alignment represent poorly conserved inserts that are not shown. The cysteine residues that are essential for Zn-binding are shown by reverse shading. The coloring is based on the consensus shown underneath the alignment; 'h' indicates hydrophobic residues (ACFILMVWY), 'p' indicates polar residues (EDKRNQHTS). Additional consensus line at the top of archaeal polymerase II alignment indicates additional conservation between polymerase ε and archaeal polymerase II: 's' indicates small residues (ACDGNPSTV). The predicted secondary structure is shown above the alignment and is compared to the NMR structure that is available for human Pol α (pdb: 1N5G)  that is shown on top of the Pol α alignment; 'H' indicates α-helix, 'E' indicates extended conformation (β-strand) and 'T' indicates a turn.