9DMR image
Entry Detail
PDB ID:
9DMR
Title:
Solution NMR structure of the calcium insensitive human LETM1 F-EF-hand domain mutant in the absence of calcium
Biological Source:
Source Organism:
Host Organism:
PDB Version:
Deposition Date:
2024-09-14
Release Date:
2025-05-07
Method Details:
Experimental Method:
Conformers Calculated:
200
Conformers Submitted:
10
Selection Criteria:
structures with the lowest energy
Macromolecular Entities
Polymer Type:polypeptide(L)
Description:Mitochondrial proton/calcium exchanger protein
Chain IDs:A
Chain Length:63
Number of Molecules:1
Biological Source:Homo sapiens
Ligand Molecules
Primary Citation
The apo LETM1 F-EF-hand adopts a closed conformation that underlies a multi-modal sensory role in mitochondria.
Febs Lett. 599 971 988 (2025)
PMID: 39927520 DOI: 10.1002/1873-3468.70006

Abstact

Leucine zipper EF-hand containing transmembrane protein-1 (LETM1) plays a critical role in mitochondrial function, with haploinsufficiency linked to Wolf-Hirschhorn syndrome. Here, we present the solution NMR structure of the calcium (Ca2+)-depleted LETM1 EF-hand domain, revealing a closed conformation facilitated by a distinct F1-helix pivot rather than decreased interhelical angle. Further, we observe regiospecific unfolding in response to hot and cold denaturation and show H662 has a pKa in-line with physiological pH fluctuations. Finally, we demonstrate Ca2+-dependent transient interactions between the EF-hand and other LETM1 or GHITM protein domains. Collectively, our data reveal the apo-to-holo structural dynamics and mechanisms underlying the multi-modal sensing by the LETM1 EF-hand domain, highlighting its role as an adaptable regulatory element within the mitochondrial matrix.

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Primary Citation of related structures