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E809K

Category 3/4 — Most DruggablePathogenicLumenal · predictedσ-1 candidateEditorial
GlutamateLysine at position 809 · C-terminal lumenal domain (653-869) · WFS1 (Wolframin)

Glutamate → Lysine at position 809 in wolframin's C-terminal lumenal domain. ClinVar Pathogenic, associated with Wolfram-like syndrome. AlphaMissense 0.718 (moderately pathogenic), DynaMut2 ΔΔG +0.41 kcal/mol — STABILISING. A clean charge-flip variant with structural stabilization.

Interactive 3D Structure

Wild-type reference
Wild-type E809 — polar contact to K811
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DynaMut2 mutant · E809K
Mutant K809 — polar contact to S807 lost (3 contacts lost)
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Bond changes · DynaMut2 interaction analysis

3 lost0 gained3 preserved
Interaction typeWild-type partnerMutant partnerStatus
Polar contactS807S807Preserved
Polar contactK811K811Preserved
Polar contactI863Lost
Van der WaalsK811Lost
Van der WaalsI863Lost
HydrophobicI863I863Preserved

Lost / gained / preserved interatomic contacts at the variant residue, from the DynaMut2 (Arpeggio) interaction analysis of the wild-type and energy-minimized mutant structures.

Computational Predictions

DynaMut2 ΔΔG
0.41kcal/mol
Stabilising — mild
AlphaMissense
0.718
LPath
AlphaFold pLDDT
83
model confidence
Schema
Cat 3/4
Category 3/4 — Most Druggable

Clinical Evidence

ClinVar classificationPathogenic
Review statuscriteria provided, multiple submitters, no conflicts
Associated conditionsWolfram-like syndrome
InheritanceDocumented in association with Wolfram-like syndrome. AD-leaning presentation.
Population frequency (gnomAD v4)Absent from gnomAD v4
cDNA changec.2425G>A
ClinVar accessionVCV000215413
Last evaluated2025/10/09 00:00

Not observed in ~730k individuals — consistent with a rare allele (ACMG PM2_supporting).

Structural Context

Position 809 sits in wolframin's C-terminal lumenal domain. The AlphaFold model places E809 within 5 Å of SER808 (2.5 Å), PHE810 (2.5 Å), SER807 (4.3 Å), LYS811 (4.3 Å), and ILE863 (4.8 Å, long-range). The local environment contains a nearby existing lysine (K811) — the wild-type E809 may have formed an intramolecular salt bridge with K811.

Replacing glutamate with lysine reverses the charge sign at position 809. The E809-K811 salt bridge breaks; the local environment now has two adjacent positive charges (K809 and K811) instead of one positive and one negative. The DynaMut2 ΔΔG of +0.41 (stabilising) reflects that the new local geometry is more energetically favorable than the wild-type — likely because both lysines can extend their flexible side chains toward solvent.

Yet AlphaMissense places this at 0.718 (moderately pathogenic, above the 0.564 likely-pathogenic threshold) and ClinVar classifies it as Pathogenic. The mechanism is functional: the lost E809 negative charge was part of the lumenal interaction surface; the introduced K809 creates a new positive patch that disrupts whatever partner recognition the wild-type surface enabled.

Amino-acid chemistry
Glutamate (E) → Lysine (K) — negatively-charged carboxylate replaced by positively-charged primary amine. Same charge-flip mechanism as E169K but in a different domain.
Position in the protein
C-terminal lumenal domain · position 809 in the ER lumen (pLDDT 83).

Druggability Assessment

Category 4 — Stable Fold, Function Disrupted. ΔΔG = +0.41 kcal/mol — fold is more stable than wild-type. AlphaMissense 0.718 plus clinical evidence confirm pathogenic mechanism is functional rather than structural.

The mechanism is charge-flip at a lumenal interaction surface — broken E809-K811 salt bridge plus a new positive patch where the wild-type contributed negative charge. Therapeutic strategy: site-directed at the recognition surface, restoring or compensating for the lost negatively-charged contribution.

Why this matters

E809K joins T361I, L402P, R685P, and others as Atlas variants where ΔΔG is positive (stabilising) but pathogenicity is real. The class is consistent: charge-flip or chemistry-flip variants where the new residue accommodates structurally but disrupts functional recognition. Drug discovery for this class requires AlphaMissense + clinical evidence — ΔΔG alone would miss them.
Therapeutic Strategy Handoff · prediction

Feed this card to Wolfram Intelligence

Download the E809K PDF below and upload it to Wolfram Intelligence to generate therapeutic-strategy proposals — guanidinium mimetics, sigma-1 agonist docking, NAC thiol-capping. NAC is already on the bench-testing list.

Download E809K PDF card ↓Strategies are AI-generated predictions, not validated therapeutics.

UniProt Domain Annotation

Chain1890 · Wolframin
Topological domain653869 · Lumenal