6JSJ

Structural analysis of a trimeric assembly of the mitochondrial dynamin-like GTPase Mgm1

Summary for 6JSJ

• Entry DOI: 10.2210/pdb6jsj/pdb
• Descriptor: Dynamin-like GTPase MGM1, mitochondrial, GUANOSINE-5'-DIPHOSPHATE, IODIDE ION (3 entities in total)
• Functional Keywords: mitochondria, fusion, mgm1, hydrolase
• Biological source: Saccharomyces cerevisiae S288c (Baker's yeast)
• Total number of polymer chains: 3
• Total formula weight: 241703.74

Authors

Yan, L.,Li, L. (deposition date: 2019-04-08, release date: 2020-02-19, Last modification date: 2020-03-11)

Primary citation

Yan, L.,Qi, Y.,Ricketson, D.,Li, L.,Subramanian, K.,Zhao, J.,Yu, C.,Wu, L.,Sarsam, R.,Wong, M.,Lou, Z.,Rao, Z.,Nunnari, J.,Hu, J.
Structural analysis of a trimeric assembly of the mitochondrial dynamin-like GTPase Mgm1.
Proc.Natl.Acad.Sci.USA, 117:4061-4070, 2020

PubMed Abstract: The fusion of inner mitochondrial membranes requires dynamin-like GTPases, Mgm1 in yeast and OPA1 in mammals, but how they mediate membrane fusion is poorly understood. Here, we determined the crystal structure of short Mgm1 (s-Mgm1) in complex with GDP. It revealed an N-terminal GTPase (G) domain followed by two helix bundles (HB1 and HB2) and a unique C-terminal lipid-interacting stalk (LIS). Dimers can form through antiparallel HB interactions. Head-to-tail trimers are built by intermolecular interactions between the G domain and HB2-LIS. Biochemical and in vivo analyses support the idea that the assembly interfaces observed here are native and critical for Mgm1 function. We also found that s-Mgm1 interacts with negatively charged lipids via both the G domain and LIS. Based on these observations, we propose that membrane targeting via the G domain and LIS facilitates the in cis assembly of Mgm1, potentially generating a highly curved membrane tip to allow inner membrane fusion.

PubMed: 32041880
DOI: 10.1073/pnas.1919116117

Experimental method

X-RAY DIFFRACTION (3.2 Å)