Ligases catalyze the joining of nucleic acid molecules enzymatically in an ATP-dependent manner. T4 DNA and RNA ligases are members of a large family of ligases and are derived from the T4 bacteriophage representing the most commonly used ligases in cloning protocols.

Thermo Scientific ligase selection table

T4 DNA Ligase T4 RNA Ligase
Applications
  • Joining dsDNA with cohesive or blunt termini
  • Joining of ds oligonucleotide linkers or adaptors to dsDNA
  • Repairing nicks in duplex DNA, RNA or DNA-RNA hybrids
  • Ligase-mediated RNA detection
  • Site-directed mutagenesis
  • Amplify fragment length polymorphisms
  • RNA 3'-end labeling with cytidine 3',5'-bis [alpha-32P] phosphate
  • Joining RNA to RNA
  • Circularization of synthetic oligonucleotides
  • Specific modifications of tRNAs
  • Oligodeoxyribonucleotide ligation to single-stranded cDNAs for 5'-RACE
  • Site-specific generation of composite primers for PCR
Substrate
  • dsDNA
  • dsRNA
  • dsDNA-RNA hybrids
  • ds poly- and oligonucleotides
  • Oligonucleotides
  • dNTPs/NTPs
  • Phosphorylated proteins
  • ssDNA
  • ssRNA
  • poly- and oligonucleotides
Reaction catalyzed ATP-dependent intra- and intermolecular formation of a phosphodiester bond between juxtaposed 5'-phosphate and 3'-hydroxyl termini in duplex DNA or RNA. ATP-dependent intra- and intermolecular formation of phosphodiester bonds between 5'-phosphate and 3'-hydroxyl termini of poly- and oligonucleotides, ssRNA and ssDNA.

ss – single-stranded
ds – double-stranded
*Although ATP is routinely used as a phosphate donor, CTP, UTP, GTP, dATP, dTTP are equally effective.