EMD-40901
Cryo-EM of the GDP-bound human dynamin polymer assembled on the membrane in the super constricted state showing the PH domain
EMD-40901
Helical reconstruction2.86 Å
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Map released: 01/05/2024
Last modified: 07/08/2024
Sample Organism:
Homo sapiens
Sample: GDP-bound human dynamin helical polymer assembled on the membrane
Fitted models: 8sz4 (Avg. Q-score: 0.344)
Deposition Authors: Jimah JR
,
Canagarajah BJ,
Hinshaw JE
Sample: GDP-bound human dynamin helical polymer assembled on the membrane
Fitted models: 8sz4 (Avg. Q-score: 0.344)
Deposition Authors: Jimah JR
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Cryo-EM structures of membrane-bound dynamin in a post-hydrolysis state primed for membrane fission.
Jimah JR
,
Kundu N
,
Stanton AE,
Sochacki KA,
Canagarajah B,
Chan L,
Strub MP,
Wang H,
Taraska JW,
Hinshaw JE
(2024) Dev Cell , 59 , 1783
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(2024) Dev Cell , 59 , 1783
Abstract:
Dynamin assembles as a helical polymer at the neck of budding endocytic vesicles, constricting the underlying membrane as it progresses through the GTPase cycle to sever vesicles from the plasma membrane. Although atomic models of the dynamin helical polymer bound to guanosine triphosphate (GTP) analogs define earlier stages of membrane constriction, there are no atomic models of the assembled state post-GTP hydrolysis. Here, we used cryo-EM methods to determine atomic structures of the dynamin helical polymer assembled on lipid tubules, akin to necks of budding endocytic vesicles, in a guanosine diphosphate (GDP)-bound, super-constricted state. In this state, dynamin is assembled as a 2-start helix with an inner lumen of 3.4 nm, primed for spontaneous fission. Additionally, by cryo-electron tomography, we trapped dynamin helical assemblies within HeLa cells using the GTPase-defective dynamin K44A mutant and observed diverse dynamin helices, demonstrating that dynamin can accommodate a range of assembled complexes in cells that likely precede membrane fission.
Dynamin assembles as a helical polymer at the neck of budding endocytic vesicles, constricting the underlying membrane as it progresses through the GTPase cycle to sever vesicles from the plasma membrane. Although atomic models of the dynamin helical polymer bound to guanosine triphosphate (GTP) analogs define earlier stages of membrane constriction, there are no atomic models of the assembled state post-GTP hydrolysis. Here, we used cryo-EM methods to determine atomic structures of the dynamin helical polymer assembled on lipid tubules, akin to necks of budding endocytic vesicles, in a guanosine diphosphate (GDP)-bound, super-constricted state. In this state, dynamin is assembled as a 2-start helix with an inner lumen of 3.4 nm, primed for spontaneous fission. Additionally, by cryo-electron tomography, we trapped dynamin helical assemblies within HeLa cells using the GTPase-defective dynamin K44A mutant and observed diverse dynamin helices, demonstrating that dynamin can accommodate a range of assembled complexes in cells that likely precede membrane fission.