Heimdall SNAREs reveal an ancestral architecture of eukaryotic SNARE complexes
- 1University of Lausanne
Abstract
SNARE proteins are central to eukaryotic cell biology, where they drive membrane fusion by assembling into four-helix bundles that bring opposing membranes into close proximity. Their ubiquitous role in intracellular membrane trafficking raises fundamental questions about their evolutionary origin and the emergence of eukaryotic cellular complexity. Here, we characterize SNARE-like proteins from Heimdallarchaeota, a lineage within the Asgard archaea that is closely related to eukaryotes. We show that a Heimdall SNARE forms a stable homotetrameric four-helix bundle in solution and determine its structure by X-ray crystallography. Strikingly, the Heimdall complex closely resembles eukaryotic SNARE complexes in its overall architecture and core organization, despite being composed of four identical subunits. Molecular dynamics simulations further reveal conserved physical features of the bundle alongside distinctive properties of its central 0-layer. These findings demonstrate that the characteristic four-helix architecture of SNAREs predates the emergence of eukaryotic cells and provide structural insight into the evolution of the membrane fusion machinery.
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BibTeX
@misc{bentahar2026heimdall,
title = {{Heimdall SNAREs reveal an ancestral architecture of eukaryotic SNARE complexes}},
author = {I. Bentahar and D. Yadav and A. Hacisuleyman and D. Fasshauer},
howpublished = {bioRxiv},
year = {2026},
month = oct,
doi = {10.64898/2026.10.19.760048},
url = {https://www.biorxiv.org/content/10.64898/2026.10.19.760048v1},
note = {Public domain},
}
RIS
TY - UNPB
TI - Heimdall SNAREs reveal an ancestral architecture of eukaryotic SNARE complexes
AU - I. Bentahar
AU - D. Yadav
AU - A. Hacisuleyman
AU - D. Fasshauer
PY - 2026
DA - 2026/10/19
PB - bioRxiv
DO - 10.64898/2026.10.19.760048
UR - https://www.biorxiv.org/content/10.64898/2026.10.19.760048v1
AB - SNARE proteins are central to eukaryotic cell biology, where they drive membrane fusion by assembling into four-helix bundles that bring opposing membranes into close proximity. Their ubiquitous role in intracellular membrane trafficking raises fundamental questions about their evolutionary origin and the emergence of eukaryotic cellular complexity. Here, we characterize SNARE-like proteins from Heimdallarchaeota, a lineage within the Asgard archaea that is closely related to eukaryotes. We show that a Heimdall SNARE forms a stable homotetrameric four-helix bundle in solution and determine its structure by X-ray crystallography. Strikingly, the Heimdall complex closely resembles eukaryotic SNARE complexes in its overall architecture and core organization, despite being composed of four identical subunits. Molecular dynamics simulations further reveal conserved physical features of the bundle alongside distinctive properties of its central 0-layer. These findings demonstrate that the characteristic four-helix architecture of SNAREs predates the emergence of eukaryotic cells and provide structural insight into the evolution of the membrane fusion machinery.
ER -