Expression, purification and biochemical characterization of Methanocaldococcus jannaschii DNA ligase

► Methanocaldococcus jannaschii DNA ligase is dependent on ATP, Mg2+ and Mn2+. ► 5′ mismatches to the nick are more serious inhibitor than 3′ mismatches. ► The C/C mismatch at the 3rd position 5′ to nick increases ligation specificity.