Structural basis of respiratory complex adaptation to cold temperatures.

ABSTRACT: In response to cold, mammals activate brown fat for respiratory-dependent thermogenesis reliant on the electron transport chain. Yet, the structural basis of respiratory complex adaptation upon cold exposure remains elusive. Herein, we combined thermoregulatory physiology and cryoelectron microscopy (cryo-EM) to study endogenous respiratory supercomplexes from mice exposed to different temperatures. A cold-induced conformation of CI:III₂ (termed type 2) supercomplex was identified with a ∼25° rotation of CIII₂ around its inter-dimer axis, shortening inter-complex Q exchange space, and exhibiting catalytic states that favor electron transfer. Large-scale supercomplex simulations in mitochondrial membranes reveal how lipid-protein arrangements stabilize type 2 complexes

SUBMITTER: Shin YC 

PROVIDER: S-EPMC11601890 | biostudies-literature | 2024 Nov

REPOSITORIES: biostudies-literature