Fig. 6
From: Reconstitution of the complete pathway of ITS2 processing at the pre-ribosome
Scheme of ITS2 removal from pre-60S particle based on in vitro C2 cleavage and 26S→25S’ pre-rRNA trimming by the Las1 complex, and 7S→5.8S pre-rRNA processing by the nuclear exosome. The Las1 complex initiates ITS2 processing by C2 cleavage and degrades the resulting 26S pre-rRNA to 25S’ pre-rRNA, which facilitates processing of the 7S pre-rRNA by the exosome. The exosome interacts with the pre-60S particle via Mtr4 interaction with Nop53. Mtr4 interacts with a composite surface of Rrp47 and Rrp6 on the exosomal side. Processing of 7S pre-rRNA releases the ITS2-associated factors like Cic1 and Rlp7 efficiently, or like Nop53 and Nop7 only partially
