Argonautes

Prokaryotic argonautes are nucleic acid guided endonucleases that can be used as programmable nucleases.  A short oligonucleotide guide (typically 16 to 18 nucleotides in length) is required.  Argonautes from different prokaryotic species may utilize either DNA or RNA guides to target DNA or RNA substrates, leading to many potential combinations of guide and substrate preferences. Upon successful recognition and binding of the guided argonaute to a complementary substrate sequence, the argonaute can introduce a break in the phosphodiester backbone of the substrate.

The list of known prokaryotic argonautes is continually growing as the field expands. Some examples of DNA:DNA argonautes (meaning DNA-guided DNA-endonuclease) include those from Pyrococcus furiosus (PfAgo), Thermus thermophilus (TtAgo), and Methanocaldococcus jannaschii (MjAgo).  RNA:DNA argonautes include those from Marinitoga piezophila (MpAgo), Thermotoga profunda (TpAgo), and Rhodobacter sphaeroides (RsAgo). DNA:RNA argonautes include those from Aquifex aeolicus (AaAgo) and (with reduced activity) Thermus thermophilus (TtAgo). Finally, RNA:RNA argonautes include those from Marinitoga piezophila (MpAgo), and for comparison, eukaryotic argonaute human (AGO2).

NEB now offers the first commercially available argonaute Tth Argonaute (TtAgo) (NEB #M0665), a DNA-guided DNA-endonuclease for in vitro applications.