PMID: 16740483

Authors:

Muziol T, Pineda-Molina E, Ravelli RB, Zamborlini A, Usami Y, Gottlinger H, Weissenhorn W

Title:

Structural basis for budding by the ESCRT-III factor CHMP3.

Journal:

Dev Cell. 2006 Jun;10(6):821-30.

Abstract:

The vacuolar protein sorting machinery regulates multivesicular body biogenesis and is selectively recruited by enveloped viruses to support budding. Here we report the crystal structure of the human ESCRT-III protein CHMP3 at 2.8 A resolution. The core structure of CHMP3 folds into a flat helical arrangement that assembles into a lattice, mainly via two different dimerization modes, and unilaterally exposes a highly basic surface. The C terminus, the target for Vps4-induced ESCRT disassembly, extends from the opposite side of the membrane targeting region. Mutations within the basic and dimerization regions hinder bilayer interaction in vivo and reverse the dominant-negative effect of a truncated CHMP3 fusion protein on HIV-1 budding. Thus, the final steps in the budding process may include CHMP protein polymerization and lattice formation on membranes by employing different bilayer-recognizing surfaces, a function shared by all CHMP family members.