From Structure-Function Analyses to Protein Engineering for Practical Applications of DNA Ligase

Figure 2

Conserved sequence elements define a superfamily of covalent nucleotidyltransferases. Six collinear sequence elements, designated as motifs I, III, IIIa, IV, V, and VI, are conserved in capping enzymes and ligases. The amino acid sequences are aligned for the DNA ligases from Chlorella virus (ChV), bacteriophage T7 (T7), Pyrococcus furiosus (Pfu), Sulfolobus solfataricus (Sso), and human (Hu). The number of intervening amino acid residues is indicated. Conserved residues are highlighted in red (nucleotidyltransferases) and blue (DNA and RNA ligases).