Database of articles cited by EMDB/PDB/SASBDB data

Keywords
Structure methods	All X-ray diffraction NMR electron microscopy small angle scattering neutron diffraction fiber diffraction powder diffraction infrared spectroscopy EPR fluorescence transfer theoretical model Hybrid
Author
Journal
IF	>30 >20 >10 >5 all

Title	An N-terminal helix of Lsm11 stabilizes CPSF73 in U7 snRNP for histone pre-mRNA 3'-end processing.
Journal, issue, pages	Nucleic Acids Res, Vol. 54, Issue 1, Year 2026
Publish date	Jan 5, 2026
Authors	Anthony Desotell / William F Marzluff / Zbigniew Dominski / Liang Tong /
PubMed Abstract	The U7 snRNP (small nuclear ribonucleoprotein) is responsible for the 3'-end processing of replication-dependent histone messenger RNA precursors (pre-mRNAs). A helix in the Lsm11 N-terminal ...The U7 snRNP (small nuclear ribonucleoprotein) is responsible for the 3'-end processing of replication-dependent histone messenger RNA precursors (pre-mRNAs). A helix in the Lsm11 N-terminal extension contacts the metallo-β-lactamase domain of the U7 snRNP endonuclease CPSF73. We mutated or deleted this helix and found that the mutant machineries had substantially reduced cleavage activity toward the pre-mRNA. Our cryo-electron microscopy (cryo-EM) studies indicated that the helix was important for helping to hold CPSF73 in its correct position for the cleavage reaction. We also reconstituted a wild-type U7 snRNP in complex with a methylated, noncleavable pre-mRNA. We observed that CPSF73 could achieve an open conformation independent of RNA binding to its active site. Finally, we found that a previously uninterpreted EM density for a small helix at the CPSF73-CPSF100 interface belonged to the C-terminal end of CstF77, copurified from insect cells and highly conserved among CstF77 homologs. This CstF77 binding site had a small effect on the cleavage activity of U7 snRNP. Overall, our studies have revealed the importance of the conserved helix in the Lsm11 N-terminal extension for U7 snRNP, provided structural evidence that CPSF73 can achieve an open, active conformation without RNA binding in its active site, and identified a previously unknown binding site for CstF77 in CPSF100.
External links	Nucleic Acids Res / PubMed:41495886 / PubMed Central
Methods	EM (single particle)
Resolution	2.82 - 3.85 Å
Structure data	49161 9n96 EMDB-49161: CryoEM structure of U7 Sm Ring in complex with symplekin N-terminal domain PDB-9n96: CRYO-EM STRUCTURE OF human U7 SM RING IN COMPLEX WITH SYMPLEKIN N-TERMINAL DOMAIN Method: EM (single particle) / Resolution: 3.18 Å 49206 9nb1 EMDB-49206, PDB-9nb1: CRYO-EM STRUCTURE OF human U7 SNRNP WITH MUTANT LSM11 that disrupts contacts with CPSF73 Method: EM (single particle) / Resolution: 3.85 Å 49389 9ngo EMDB-49389: CRYO-EM STRUCTURE OF HUMAN U7 SNRNP WITH METHYLATED *H2A SUBSTRATE PRE-MRNA FOCUS MAP** PDB-9ngo: CRYO-EM STRUCTURE OF HUMAN U7 SNRNP WITH METHYLATED noncleavable H2A* SUBSTRATE PRE-MRNA (FOCUS MAP) Method: EM (single particle) / Resolution: 3.01 Å 49402 9nh5 EMDB-49402, PDB-9nh5: CRYO-EM STRUCTURE OF HUMAN U7 SNRNP WITH METHYLATED noncleavable H2A* SUBSTRATE PRE-MRNA (core region) Method: EM (single particle) / Resolution: 2.82 Å 49403 9nh6 EMDB-49403, PDB-9nh6: CRYO-EM STRUCTURE OF HUMAN U7 SNRNP WITH METHYLATED noncleavable H2A* SUBSTRATE PRE-MRNA (COMPOSITE MAP) Method: EM (single particle) / Resolution: 2.82 Å
Chemicals	ChemComp-ZN: Unknown entry
Source	homo sapiens (human) mus musculus (house mouse) trichoplusia ni (cabbage looper)
Keywords	RNA BINDING PROTEIN/RNA / Symplekin / 3' end processing / U7 snRNP / Histone pre-mRNA / RNA BINDING PROTEIN / RNA BINDING PROTEIN-RNA complex / Methylated RNA