Crystal structure of nucleotide-free dynamin

Area of Science:

• Biochemistry
• Molecular Biology
• Structural Biology

Background:

• Dynamin is a crucial mechanochemical GTPase involved in vesicle scission at clathrin-coated pits.
• The precise molecular mechanisms underlying dynamin oligomerization and GTP-hydrolysis-dependent function remain elusive.

Purpose of the Study:

• To elucidate the molecular architecture of human dynamin 1 in its nucleotide-free state.
• To investigate the oligomerization patterns and domain interactions of dynamin.
• To propose a structural model for dynamin's mechanochemical coupling.

Main Methods:

• X-ray crystallography of human dynamin 1.
• Analysis of domain architecture and oligomeric assembly.

Main Results:

• The crystal structure of nucleotide-free human dynamin 1 revealed a four-domain architecture (GTPase, bundle signaling element, stalk, PH domain).
• Dynamin 1 molecules oligomerized through a novel criss-cross arrangement of their stalk domains in the crystal lattice.
• Interactions between stalk, PH domain, and bundle signaling element of adjacent molecules were identified.

Conclusions:

• The identified intricate domain interactions provide a structural basis for understanding disease-related mutations in dynamin 2.
• The findings suggest a plausible structural model for dynamin's mechanochemical coupling, integrating previous functional models.