3VYX

Structural insights into RISC assembly facilitated by dsRNA binding domains of human RNA helicase (DHX9)

Summary for 3VYX

• Entry DOI: 10.2210/pdb3vyx/pdb
• Related: 3VYY
• Descriptor: ATP-dependent RNA helicase A, RNA (5'-R(P*GP*CP*GP*CP*GP*CP*GP*CP*GP*C)-3') (3 entities in total)
• Functional Keywords: protein-dsrna complex, dsrbd fold, dsrna binding, protein-protein interaction, hydrolase-rna complex, hydrolase/rna
• Biological source: Homo sapiens (human); More
• Cellular location: Nucleus, nucleolus: Q08211
• Total number of polymer chains: 3
• Total formula weight: 19490.73

Authors

Yuan, Y.A.,Fu, Q. (deposition date: 2012-10-05, release date: 2013-02-13, Last modification date: 2024-03-20)

Primary citation

Fu, Q.,Yuan, Y.A.
Structural insights into RISC assembly facilitated by dsRNA-binding domains of human RNA helicase A (DHX9).
Nucleic Acids Res., 41:3457-3470, 2013

PubMed Abstract: Intensive research interest has focused on small RNA-processing machinery and the RNA-induced silencing complex (RISC), key cellular machines in RNAi pathways. However, the structural mechanism regarding RISC assembly, the primary step linking small RNA processing and RNA-mediated gene silencing, is largely unknown. Human RNA helicase A (DHX9) was reported to function as an RISC-loading factor, and such function is mediated mainly by its dsRNA-binding domains (dsRBDs). Here, we report the crystal structures of human RNA helicase A (RHA) dsRBD1 and dsRBD2 domains in complex with dsRNAs, respectively. Structural analysis not only reveals higher siRNA duplex-binding affinity displayed by dsRBD1, but also identifies a crystallographic dsRBD1 pair of physiological significance in cooperatively recognizing dsRNAs. Structural observations are further validated by isothermal titration calorimetric (ITC) assay. Moreover, co-immunoprecipitation (co-IP) assay coupled with mutagenesis demonstrated that both dsRBDs are required for RISC association, and such association is mediated by dsRNA. Hence, our structural and functional efforts have revealed a potential working model for siRNA recognition by RHA tandem dsRBDs, and together they provide direct structural insights into RISC assembly facilitated by RHA.

PubMed: 23361462
DOI: 10.1093/nar/gkt042

Experimental method

X-RAY DIFFRACTION (2.29 Å)