T321P

Category 4 — Stable Fold, Function DisruptedLikely pathogenicTransmembrane · predictedEditorial

Threonine → Proline at position 321 · TM1 (314-334), helical transmembrane · WFS1 (Wolframin)

Threonine → Proline at position 321 inside TM1. ClinVar Likely pathogenic. AlphaMissense 0.261 (below threshold) — AM under-call. DynaMut2 ΔΔG +0.13 kcal/mol — essentially neutral. Same position as T321R, proline-introduction at TM1 start.

Interactive 3D Structure

Wild-type reference

Wild-type T321 — hydrogen bond to N325

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DynaMut2 mutant · T321P

Mutant P321 — hydrogen bond to I319 lost (3 contacts lost)

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Bond changes · DynaMut2 interaction analysis

3 lost2 gained3 preserved

Interaction type	Wild-type partner	Mutant partner	Status
Hydrogen bond	I319	—	Lost
Hydrogen bond	N325	N325	Preserved
Polar contact	I319	I319	Preserved
Polar contact	I324	—	Lost
Polar contact	N325	N325	Preserved
Van der Waals	—	I319	Gained
Van der Waals	—	N325	Gained
Hydrophobic	I319	—	Lost

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

0.13kcal/mol

Stabilising — mild

AlphaMissense

0.261

LBen

AlphaFold pLDDT

model confidence

Schema

Cat 4

Category 4 — Stable Fold, Function Disrupted

Clinical Evidence

ClinVar classificationLikely pathogenic

Review statuscriteria provided, single submitter

Associated conditions(no specific conditions catalogued)

InheritanceInheritance not specified.

Population frequency (gnomAD v4)Ultra-rare · AF 0.00020%

cDNA changec.961A>C

ClinVar accessionVCV000918064

Last evaluated2025/03/10 00:00

Observed at very low frequency in gnomAD.

Structural Context

Position 321 sits at the start of TM1. Same neighbor environment as T321R: HIS322 (2.5 Å), PRO320 (2.5 Å — adjacent proline!), ILE319 (3.8 Å), ILE324 (4.4 Å), HIS323 (4.5 Å).

Replacing T321 with proline creates a Pro-Pro motif (P320-P321) in the cytoplasmic-to-TM1 boundary region. Two adjacent prolines produce a rigid backbone segment with restricted conformational options — similar to the L723P/P724S Pro-Pro region in the lumenal domain.

The ΔΔG of +0.13 (essentially neutral) reflects fold accommodation through local rearrangement. AlphaMissense's 0.261 below threshold is AM under-call. ClinVar Likely Pathogenic establishes clinical relevance.

Amino-acid chemistry

Threonine (T) → Proline (P) — small polar hydroxyl replaced by rigid helix-breaking residue.

Position in the protein

TM1 (residues 314–334) · position 321 near the start of TM1 (pLDDT 75).

Druggability Assessment

Category 4 — Stable Fold, Function Disrupted (AM under-call). ΔΔG = +0.13 — fold essentially unchanged. AlphaMissense 0.261 below threshold.

Mechanism is creation of a P320-P321 Pro-Pro motif at the TM1 boundary, altering TM1 insertion geometry. Therapeutic strategy: site-directed at TM1 start.

Why this matters

T321P + T321R both at position 321, both AM under-calls, both ClinVar pathogenic. The dense TM1 variant cluster (W314R, H313Y, T321R, T321P, H323R, A326E) makes TM1 a high-confidence multi-variant therapeutic target.

Therapeutic Strategy Handoff · prediction

Feed this card to Wolfram Intelligence

Download the T321P 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 T321P PDF card ↓Strategies are AI-generated predictions, not validated therapeutics.

UniProt Domain Annotation

Chain1–890 · Wolframin

Transmembrane314–334 · Helical

Region1–321 · Interaction with ATP6V1A