8HIP image
Entry Detail
PDB ID:
8HIP
EMDB ID:
Title:
dsRNA transporter
Biological Source:
Source Organism:
Host Organism:
PDB Version:
Deposition Date:
2022-11-21
Release Date:
2023-11-29
Method Details:
Experimental Method:
Resolution:
2.77 Å
Aggregation State:
PARTICLE
Reconstruction Method:
SINGLE PARTICLE
Macromolecular Entities
Polymer Type:polypeptide(L)
Description:Systemic RNA interference defective protein 1
Chain IDs:A (auth: B), B (auth: A)
Chain Length:776
Number of Molecules:2
Biological Source:Homo sapiens
Primary Citation
Structural insights into double-stranded RNA recognition and transport by SID-1.
Nat.Struct.Mol.Biol. 31 1095 1104 (2024)
PMID: 38664565 DOI: 10.1038/s41594-024-01276-9

Abstact

RNA uptake by cells is critical for RNA-mediated gene interference (RNAi) and RNA-based therapeutics. In Caenorhabditis elegans, RNAi is systemic as a result of SID-1-mediated double-stranded RNA (dsRNA) across cells. Despite the functional importance, the underlying mechanisms of dsRNA internalization by SID-1 remain elusive. Here we describe cryogenic electron microscopy structures of SID-1, SID-1-dsRNA complex and human SID-1 homologs SIDT1 and SIDT2, elucidating the structural basis of dsRNA recognition and import by SID-1. The homodimeric SID-1 homologs share conserved architecture, but only SID-1 possesses the molecular determinants within its extracellular domains for distinguishing dsRNA from single-stranded RNA and DNA. We show that the removal of the long intracellular loop between transmembrane helix 1 and 2 attenuates dsRNA uptake and systemic RNAi in vivo, suggesting a possible endocytic mechanism of SID-1-mediated dsRNA internalization. Our study provides mechanistic insights into dsRNA internalization by SID-1, which may facilitate the development of dsRNA applications based on SID-1.

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Primary Citation of related structures