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C733G

Category 3/4 — Most DruggableLikely pathogenicLumenal · predictedσ-1 candidateEditorial
CysteineGlycine at position 733 · C-terminal lumenal domain (653-869) · WFS1 (Wolframin)

Cysteine → Glycine at position 733 in wolframin's C-terminal lumenal domain. ClinVar Likely pathogenic for Wolfram syndrome 1. AlphaMissense 0.912, DynaMut2 ΔΔG -1.15 kcal/mol (destabilising). Cysteine-removal variant with potential disulfide partner C765 in spatial proximity.

Interactive 3D Structure

Wild-type reference
Wild-type C733 — hydrogen bond to W730
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DynaMut2 mutant · C733G
Mutant G733 — hydrogen bond to P764 lost (2 contacts lost)
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Bond changes · DynaMut2 interaction analysis

2 lost0 gained7 preserved
Interaction typeWild-type partnerMutant partnerStatus
Hydrogen bondD729D729Preserved
Hydrogen bondW730W730Preserved
Hydrogen bondP764Lost
Polar contactD729D729Preserved
Polar contactW730W730Preserved
Polar contactM731M731Preserved
Polar contactC765C765Preserved
Van der WaalsM731M731Preserved
HydrophobicC765Lost

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
-1.15kcal/mol
Destabilising — moderate
AlphaMissense
0.912
LPath
AlphaFold pLDDT
89
model confidence
Schema
Cat 3/4
Category 3/4 — Most Druggable

Clinical Evidence

ClinVar classificationLikely pathogenic
Review statuscriteria provided, single submitter
Associated conditionsWolfram syndrome 1
InheritanceWolfram syndrome 1 (AR) documented.
Population frequency (gnomAD v4)Absent from gnomAD v4
cDNA changec.2197T>G
ClinVar accessionVCV001264333
Last evaluated1/01/01 00:00

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

Structural Context

Position 733 sits in wolframin's C-terminal lumenal domain. The AlphaFold model places C733 within 5 Å of ARG732 (2.4 Å — same R732 as G736R neighbor), LEU734 (2.5 Å), CYS765 (3.5 Å — possible disulfide partner!), TRP730 (3.7 Å), and ASP729 (4.0 Å).

The C733-C765 distance of 3.5 Å is consistent with a possible disulfide bond in the oxidizing ER lumen. The Atlas's C690R/C690Y cards discuss a similar C673-C690 inferred disulfide; C733-C765 may be a second analogous structural disulfide in the lumenal domain.

Replacing C733 with glycine eliminates this potential disulfide entirely. The fold loses a major structural anchor. The |ΔΔG| of 1.15 reflects this — meaningful destabilization for a single substitution. AlphaMissense's 0.912 + Wolfram 1 clinical evidence confirm severe functional consequence.

Amino-acid chemistry
Cysteine (C) → Glycine (G) — thiol-bearing residue replaced by smallest amino acid. Loss of disulfide-bond potential plus loss of side chain entirely.
Position in the protein
C-terminal lumenal domain · position 733 in the ER lumen (pLDDT 88).

Druggability Assessment

Category 3/4 — Most Druggable. |ΔΔG| = 1.15 — fold survives at meaningful cost. AlphaMissense 0.912 + Wolfram 1 confirm severe functional consequence.

Mechanism is loss of an inferred C733-C765 disulfide bond. Therapeutic strategy: site-directed at the C765 partner site, potentially with a small molecule that bridges the two former cysteines.

Why this matters

C733-C765 is the second possible disulfide pair identified in the Atlas (after C673-C690). The lumenal domain appears to use multiple structural disulfides; variants at any of these cysteines disrupt the fold.
Therapeutic Strategy Handoff · prediction

Feed this card to Wolfram Intelligence

Download the C733G 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 C733G PDF card ↓Strategies are AI-generated predictions, not validated therapeutics.

UniProt Domain Annotation

Chain1890 · Wolframin
Topological domain653869 · Lumenal