5NPG

Solution structure of Drosophila melanogaster Loquacious dsRBD1

Summary for 5NPG

• Entry DOI: 10.2210/pdb5npg/pdb
• NMR Information: BMRB: 34124
• Descriptor: Loquacious, isoform F (1 entity in total)
• Functional Keywords: dsrbd, rna interference, sirna, rna binding protein
• Biological source: Drosophila melanogaster (Fruit fly)
• Total number of polymer chains: 1
• Total formula weight: 9105.57

Authors

Tants, J.-N.,Fesser, S.,Kern, T.,Stehle, R.,Geerlof, A.,Wunderlich, C.,Hartlmuller, C.,Boettcher, R.,Kunzelmann, S.,Lange, O.,Kreutz, C.,Foerstemann, K.,Sattler, M. (deposition date: 2017-04-16, release date: 2017-10-04, Last modification date: 2024-05-15)

Primary citation

Tants, J.N.,Fesser, S.,Kern, T.,Stehle, R.,Geerlof, A.,Wunderlich, C.,Juen, M.,Hartlmuller, C.,Bottcher, R.,Kunzelmann, S.,Lange, O.,Kreutz, C.,Forstemann, K.,Sattler, M.
Molecular basis for asymmetry sensing of siRNAs by the Drosophila Loqs-PD/Dcr-2 complex in RNA interference.
Nucleic Acids Res., 45:12536-12550, 2017

PubMed Abstract: RNA interference defends against RNA viruses and retro-elements within an organism's genome. It is triggered by duplex siRNAs, of which one strand is selected to confer sequence-specificity to the RNA induced silencing complex (RISC). In Drosophila, Dicer-2 (Dcr-2) and the double-stranded RNA binding domain (dsRBD) protein R2D2 form the RISC loading complex (RLC) and select one strand of exogenous siRNAs according to the relative thermodynamic stability of base-pairing at either end. Through genome editing we demonstrate that Loqs-PD, the Drosophila homolog of human TAR RNA binding protein (TRBP) and a paralog of R2D2, forms an alternative RLC with Dcr-2 that is required for strand choice of endogenous siRNAs in S2 cells. Two canonical dsRBDs in Loqs-PD bind to siRNAs with enhanced affinity compared to miRNA/miRNA* duplexes. Structural analysis, NMR and biophysical experiments indicate that the Loqs-PD dsRBDs can slide along the RNA duplex to the ends of the siRNA. A moderate but notable binding preference for the thermodynamically more stable siRNA end by Loqs-PD alone is greatly amplified in complex with Dcr-2 to initiate strand discrimination by asymmetry sensing in the RLC.

PubMed: 29040648
DOI: 10.1093/nar/gkx886

Experimental method

SOLUTION NMR