T4 DNA ligase
T4 DNA ligase is purified from E.coli stream carrying a plasmid with a cloned gene 30 of phage T4.
Enzyme catalyzes the formation of phosphodiester bonds between juxtaposed 5’-phosphate and 3’-hydroxyl termini in duplex DNA or RNA with blunt or cohesive ends.
Enzyme requires ATP as a cofactor for activity. The presence of NaCl and KCl in concentrations above 200mM inhibits the activity of T4 DNA ligase.
● fast ligation of DNA fragments (cohesive and blunt ends).
● repairing of single-stranded nicks in duplex DNA, RNA or DNA-RNA hybrids. It has no activity against single-stranded nucleic acids.
T4 RNA Ligase 1
T4 RNA ligase 1 catalyzes the ATP-dependent ligation of single-stranded 5′-phosphoryl terminated nucleic acid donor to single-stranded 3′-hydroxyl terminated nucleic acid acceptor through the formation of a 3’→5′ phosphodiester bond. Substrates include single-stranded RNA and DNA as well as numerous nucleotide derivatives.