biostudies-literatureHuang JU.S. Department of Health & Human Services | NIH | National Institute of General Medical Sciences (NIGMS)NIGMS NIH HHS3288https://www.ebi.ac.uk/biostudies/studies/S-EPMC11976907biostudies-literatureUnknown16(1)Rixosome is a conserved, multi-subunit protein complex that has critical roles in ribosome biogenesis and silencing of Polycomb target genes. The subunits of human rixosome include PELP1, WDR18, TEX10, LAS1L and NOL9, with LAS1L providing the endoribonuclease activity and NOL9 the RNA 5' kinase activity. We report here cryo-EM structures of the human PELP1-WDR18-TEX10 and LAS1L-NOL9 complexes and a lower-resolution model of the human PELP1-WDR18-LAS1L complex. The structures reveal the overall organization of the human rixosome core scaffold of PELP1-WDR18-TEX10-LAS1L and indicate how the LAS1L-NOL9 endonuclease/kinase catalytic module is recruited to this core scaffold. Each TEX10 molecule has two regions of contact with WDR18, while the helix at the C terminus of WDR18 interacts with theNature communicationsMolecular insights into the overall architecture of human rixosome.PMC11976907R35 GM118093R35GM118093U24 GM129539Huang JTong LfalseMolecular insights into the overall architecture of human rixosome.Rixosome is a conserved, multi-subunit protein complex that has critical roles in ribosome biogenesis and silencing of Polycomb target genes. The subunits of human rixosome include PELP1, WDR18, TEX10, LAS1L and NOL9, with LAS1L providing the endoribonuclease activity and NOL9 the RNA 5' kinase activity. We report here cryo-EM structures of the human PELP1-WDR18-TEX10 and LAS1L-NOL9 complexes and a lower-resolution model of the human PELP1-WDR18-LAS1L complex. The structures reveal the overall organization of the human rixosome core scaffold of PELP1-WDR18-TEX10-LAS1L and indicate how the LAS1L-NOL9 endonuclease/kinase catalytic module is recruited to this core scaffold. Each TEX10 molecule has two regions of contact with WDR18, while the helix at the C terminus of WDR18 interacts with the2025-01-01T00:00:00Z2025 Apr2026-06-03T01:17:51.061Z2026-04-22T03:12:18.45ZS-EPMC119769074019536510.1038/s41467-025-58732-3