InterPro domain: IPR043172

Prp8 is the largest and most highly conserved spliceosomal protein and is considered a master regulator of the spliceosome. It forms a salt-stable complex with the Brr2 helicase that is required for spliceosome catalytic activation and disassembly, and with the Snu114 GTPase that regulates Brr2 activity. Prp8 consists of a phylogenetically conserved Rnase H fold along with Prp8-specific elements. The function of this domain is to help assemble and stabilise the spliceosomal catalytic core and coordinate the activities of other splicing factors [ 1 ]. The overall structure of Rnase H is reminiscent of a left-hand mitten, in which a central six-stranded mixed beta-sheet and the surrounding alpha-helices of the N-terminal domain correspond to the palm, an extended beta-hairpin of the N-terminal domain comprises the thumb and the alpha-helical C-terminal domain represents the fingers [ 2 ].

This entry represents the palm region of the Rnase H domain which also includes the beta-hairpin thumb.

1. Structure and function of an RNase H domain at the heart of the spliceosome. EMBO J. 27, 2929-40