FIG. 2.

Alignment of vaccinia virus (VAC) and LdMNPV DNA ligases. The six conserved sequence motifs comprising the catalytic domain are boxed and designated I, III, IIIa, IV, V, and VI. Identical amino acids are indicated by white letters within black boxes, and similar amino acids are denoted by shaded boxes. Dots indicate gaps. Amino acid numbers are indicated on the left. Asterisks designate the amino acids in the vaccinia virus DNA ligase that have been determined to be essential for activity of the enzyme (40). The vaccinia virus sequence accession no. is U94848.