bI3 intron splicing complex cellular_component GO:0106392 Aprotein complex required for the splicing of intron 3 of the cytochrome b (COB) gene. In S. cerevisiae, the complex contains the maturase bI3 (which derives from one of the products of the splicing), the MRS1 cofactor and the intron 4 of the cytochrome b pre-mRNA. The two proteins stimulate the ribozyme activity of the pre-mRNA which autoctalyse a group I intron splicing. hjd 2021-10-08T14:43:33Z Intact:EBI-16426213 endoribonuclease complex