9LKX

local refinement of FEM1B bound with PLD6

Summary for 9LKX

• Entry DOI: 10.2210/pdb9lkx/pdb
• EMDB information: 63187
• Descriptor: Protein fem-1 homolog B, Mitochondrial cardiolipin hydrolase (2 entities in total)
• Functional Keywords: ubiquitination e3 ligase, cryo-em, protein binding
• Biological source: Homo sapiens (human); More
• Total number of polymer chains: 2
• Total formula weight: 93239.35

Authors

Zhao, S.,Xu, C. (deposition date: 2025-01-16, release date: 2025-04-09, Last modification date: 2025-05-07)

Primary citation

Raiff, A.,Zhao, S.,Bekturova, A.,Zenge, C.,Mazor, S.,Chen, X.,Ru, W.,Makaros, Y.,Ast, T.,Ordureau, A.,Xu, C.,Koren, I.
TOM20-driven E3 ligase recruitment regulates mitochondrial dynamics through PLD6.
Nat.Chem.Biol., 2025

PubMed Abstract: Mitochondrial homeostasis is maintained through complex regulatory mechanisms, including the balance of mitochondrial dynamics involving fusion and fission processes. A central player in this regulation is the ubiquitin-proteasome system (UPS), which controls the degradation of pivotal mitochondrial proteins. In this study, we identified cullin-RING E3 ligase 2 (CRL2) and its substrate receptor, FEM1B, as critical regulators of mitochondrial dynamics. Through proteomic analysis, we demonstrate here that FEM1B controls the turnover of PLD6, a key regulator of mitochondrial dynamics. Using structural and biochemical approaches, we show that FEM1B physically interacts with PLD6 and that this interaction is facilitated by the direct association of FEM1B with the mitochondrial import receptor TOM20. Ablation of FEM1B or disruption of the FEM1B-TOM20 interaction impairs PLD6 degradation and induces mitochondrial defects, phenocopying PLD6 overexpression. These findings underscore the importance of FEM1B in maintaining mitochondrial morphology and provide further mechanistic insights into how the UPS regulates mitochondrial homeostasis.

PubMed: 40263465
DOI: 10.1038/s41589-025-01894-4

Experimental method

ELECTRON MICROSCOPY (3.76 Å)