Structural investigation of human U6 snRNA recognition by spliceosomal recycling factor SART3 RNA recognition motifs
- PMID: 41046346
- DOI: 10.1111/febs.70275
Structural investigation of human U6 snRNA recognition by spliceosomal recycling factor SART3 RNA recognition motifs
Abstract
Human spliceosome-associated factor 3, SART3, is a key factor in spliceosome recycling and engages with U6 small nuclear RNA (snRNA) to promote the formation of the U4/U6 small nuclear ribonucleoprotein complex. Unlike its counterpart U4/U6 snRNA-associated-splicing factor PRP24 (Prp24) from Saccharomyces cerevisiae, which uses four RNA recognition motifs (RRMs) for the U6 snRNA interaction, SART3 has two RRMs at its C terminus. Here, we demonstrate that SART3 binds U6 snRNA as a dimer, and four RRM subunits recognize the asymmetric bulge of U6 snRNA. SART3 RRMs adopt a tandem βαββαβ motif of the canonical RRM fold to interact with the U6 bulge region via a conserved electropositive surface. We identified the cognate U6 elements that specifically bind SART3 RRM1, which is distinct from the Prp24-U6 interactions in yeast. Our findings suggest a divergent RRM binding mechanism for U6 snRNA recognition during spliceosome assembly and recycling.
Keywords: RNA recognition motif; SART3; U6 snRNA; solution structure.
© 2025 The Author(s). The FEBS Journal published by John Wiley & Sons Ltd on behalf of Federation of European Biochemical Societies.
References
-
- Will CL & Luhrmann R (2011) Spliceosome structure and function. Cold Spring Harb Perspect Biol 3, a003707.
-
- Wang E & Aifantis I (2020) RNA splicing and cancer. Trends Cancer 6, 631–644.
-
- Montes M, Sanford BL, Comiskey DF & Chandler DS (2019) RNA splicing and disease: animal models to therapies. Trends Genet 35, 68–87.
-
- Scotti MM & Swanson MS (2016) RNA mis‐splicing in disease. Nat Rev Genet 17, 19–32.
-
- Didychuk AL, Butcher SE & Brow DA (2018) The life of U6 small nuclear RNA, from cradle to grave. RNA 24, 437–460.
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