8J6M

SIDT1 protein

Summary for 8J6M

• Entry DOI: 10.2210/pdb8j6m/pdb
• EMDB information: 36008
• Descriptor: Green fluorescent protein,SID1 transmembrane family member 1, CHOLESTEROL, ZINC ION, ... (6 entities in total)
• Functional Keywords: transport t1, transcription
• Biological source: Aequorea victoria; More
• Total number of polymer chains: 2
• Total formula weight: 251901.31

Authors

Zhang, J.T.,Jiang, D.H. (deposition date: 2023-04-26, release date: 2024-05-01, Last modification date: 2024-10-16)

Primary citation

Zhang, J.,Zhan, C.,Fan, J.,Wu, D.,Zhang, R.,Wu, D.,Chen, X.,Lu, Y.,Li, M.,Lin, M.,Gong, J.,Jiang, D.
Structural insights into double-stranded RNA recognition and transport by SID-1.
Nat.Struct.Mol.Biol., 31:1095-1104, 2024

PubMed Abstract: 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.

PubMed: 38664565
DOI: 10.1038/s41594-024-01276-9

Experimental method

ELECTRON MICROSCOPY (2.77 Å)