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Publication Abstract from PubMed

Dynamin 1-like proteins (DNM1-L) are mechanochemical GTPases that induce membrane fission in mitochondria and peroxisomes. Their mechanism depends on conformational changes driven by nucleotide and lipid cycling. Here we show the crystal structure of a mitochondrial fission dynamin (CmDnm1) from the algae Cyanidioschyzon merolae. Unlike other eukaryotic dynamin structures, CmDnm1 is in a hinge 1 closed conformation, with the GTPase domain compacted against the stalk. Within the crystal, CmDnm1 packs as a diamond-shaped tetramer that is consistent with an inactive off-membrane state. Crosslinking, photoinduced electron transfer assays, and electron microscopy verify these structures. In vitro, CmDnm1 forms concentration-dependent rings and protein-lipid tubes reminiscent of DNM1-L and classical dynamin with hinge 1 open. Our data provides a mechanism for filament collapse and membrane release that may extend to other dynamin family members. Additionally, hinge 1 closing may represent a key conformational change that contributes to membrane fission.

Structure of a mitochondrial fission dynamin in the closed conformation.,Bohuszewicz O, Low HH Nat Struct Mol Biol. 2018 Aug;25(8):722-731. doi: 10.1038/s41594-018-0097-6. Epub, 2018 Jul 30. PMID:30061604^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.