Structural insights into crista junction formation by the Mic60-Mic19 complex.

Tobias Bock-Bierbaum, Kathrin Funck, Florian Wollweber, Elisa Lisicki, Karina von der Malsburg, Alexander von der Malsburg, Janina Laborenz, Jeffrey K Noel, Manuel Hessenberger, Sibylle Jungbluth, Carola Bernert, Séverine Kunz, Dietmar Riedel, Hauke Lilie, Stefan Jakobs, Martin van der Laan, Oliver Daumke

Science advances 2022 Sep 02

filter terms:

Mitochondrial cristae membranes are the oxidative phosphorylation sites in cells. Crista junctions (CJs) form the highly curved neck regions of cristae and are thought to function as selective entry gates into the cristae space. Little is known about how CJs are generated and maintained. We show that the central coiled-coil (CC) domain of the mitochondrial contact site and cristae organizing system subunit Mic60 forms an elongated, bow tie-shaped tetrameric assembly. Mic19 promotes Mic60 tetramerization via a conserved interface between the Mic60 mitofilin and Mic19 CHCH (CC-helix-CC-helix) domains. Dimerization of mitofilin domains exposes a crescent-shaped membrane-binding site with convex curvature tailored to interact with the curved CJ neck. Our study suggests that the Mic60-Mic19 subcomplex traverses CJs as a molecular strut, thereby controlling CJ architecture and function.

Citation

PMID: 36044574

View Full Text