The AAA ATPase Vps4 binds ESCRT-III substrates through a repeating array of dipeptide-binding pockets

• DOI: 10.7554/elife.31324
• Publication Date: 2017-11-22T13:02:30Z
• Authors: Han Han; Nicole Monroe; Wesley I Sundquist; Peter S Shen; Christopher P Hill
• Keywords: AAA proteins; Helix (gastropod); Walker motifs

The hexameric AAA ATPase Vps4 drives membrane fission by remodeling and disassembling ESCRT-III filaments. Building upon our earlier 4.3 Å resolution cryo-EM structure (<xref ref-type="bibr" rid="bib29">Monroe et al., 2017</xref>), we now report a 3.2 of bound to an peptide substrate. new reveals that the approximates β-strand conformation whose helical symmetry matches five subunits it contacts directly. Adjacent make equivalent interactions with successive substrate dipeptides through two distinct classes side chain binding pockets formed primarily pore loop 1. These accommodate wide range residues, while main hydrogen bonds may help dictate substrate-binding orientation. supports ‘conveyor belt’ model translocation in which ATP allows subunit join growing end helix engage substrate, hydrolysis release promotes disassembly at lagging end.