This domain is found in eukaryotes, and is about 20 amino acids in length. It is found associated with pfam10597, pfam10596, pfam10598, pfam08083, pfam08082, pfam01398, pfam08084. There is a conserved LILR sequence motif. The domain is a selenomethionine domain in a subunit of the spliceosome. The function of PRP8 domain IV is believed to be interaction with the splicosomal core.