Mutations in the Artemis complex results in hypersensitivity to DNA double-strand break-inducing agents, such as radiation; and so people with mutations in the Artemis complex may develop radiosensitive severe combined immune deficiency (RS-SCID).
The Artemis protein has single-strand-specific 5' to 3' exonuclease activity, but it can also complex with the 469 kDa DNA-dependent protein kinase (DNA-PKcs) to gain endonuclease activity on hairpins and the 5' and 3' overhangs; the DNA-PKcs phosphorylates Artemis to give it this new function.
Some of this DNA is then deleted, and the RAG complex then induce a nick precisely at the 5' end of the heptamer.
The Artemis:DNA-PKcs complex, along with Ku and DNA ligase IV/XRCC4 dimer, can then close up the signal ends into a 'signal joint'.
This creates a junction between each joined segment, containing an unspecified number of nucleotide additions, flanked by a 2-residue palindromic sequence.