Spliceosome assembly and regulation: insights from analysis of highly reduced spliceosomes

Overview of the Cm splicing proteins present throughout one pre-mRNA splicing cycle. Proteins are colored according to incorporation into the spliceosome, whereas proteins absent in Cm are shown in transparent gray. The color scheme is as follows: Tri-snRNP (green, PDB 3JCR); Pre-B complex (orange, PDB 6AH0); B-complex (red, PDB 5O9Z); B^act complex (purple, PDB 5GM6); C* complex (blue, PDB 5MQF); P complex (no additional proteins, PDB 5YLZ).