Structures of the human spliceosomes before and after release of the ligated exon

Cryo-EM structures of the human post-catalytic spliceosome (P complex) and the human intron lariat spliceosome (ILS complex). a Structure of the human spliceosomal P complex at an average resolution of 3.0？？. Two perpendicular views are shown. Components of the P complex are color-coded and tabulated below the structure. NTC: NineTeen complex; NTR: NTC-related complex. b Structure of the human ILS complex 1 (ILS1) at an average resolution of 2.91？？. The ATPase/helicase Prp43 is yet to be loaded in the ILS1 complex. c Structure of the human ILS complex 2 (ILS2) at an average resolution of 2.86？？. Prp43 is present in the ILS2 complex, ready to disassemble the spliceosom