This domain is found in eukaryotes, and is about 20 amino acids in length. It is found associated with PF10597 PF10596 PF10598 PF08083 PF08082 PF01398 PF08084. 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.
This entry represents Prp8 domain IV, which adopts a RNase H like fold within its core structure but with little sequence similarity. Pre-mRNA-splicing factor 8 (Prp8), a spliceosome protein, interacts directly with the splice sites and branch regions of precursor-mRNAs and spliceosomal RNAs associated with catalysis of the two steps of splicing. Catalysis of RNA cleavage by RNase H-like proteins involves a two-metal mechanism in which adjacently-bound divalent magnesium ions promote hydrolysis by activation of a water nucleophile and stabilization of the transition-state. However, the Prp8 domain IV contains only one of the canonical metal-binding sites and the coordinating side chains are spatially conserved with respect to Mg2+-coordinating residues within the RNase H fold [PUBMED:18836455].