ATPase and Protease Domain Movements in the Bacterial AAA+ Protease FtsH Are Driven by Thermal Fluctuations

Research output: Contribution to journalResearch articleContributedpeer-review

Abstract

AAA+ proteases are essential players in cellular pathways of protein degradation. Elucidating their conformational behavior is key for understanding their reaction mechanism and, importantly, for elaborating our understanding of mutation-induced protease deficiencies. Here, we study the structural dynamics of the Thermotoga maritima AAA+ hexameric ring metalloprotease FtsH (TmFtsH). Using a single-molecule Forster resonance energy transfer approach to monitor ATPase and protease inter-domain conformational changes in real time, we show that TmFtsH-even in the absence of nucleotide-is a highly dynamic protease undergoing sequential transitions between five states on the second timescale. Addition of ATP does not influence the number of states or change the timescale of domain motions but affects the state occupancy distribution leading to an inter-domain compaction. These findings suggest that thermal energy, but not chemical energy, provides the major driving force for conformational switching, while ATP, through a state reequilibration, introduces directionality into this process. The TmFtsH A359V mutation, a homolog of the human pathogenic A510V mutation of paraplegin (SPG7) causing hereditary spastic paraplegia, does not affect the dynamic behavior of the protease but impairs the ATP-coupled domain compaction and, thus, may account for protease malfunctioning and pathogenesis in hereditary spastic paraplegia. (C) 2018 Elsevier Ltd. All rights reserved.

Details

Original languageEnglish
Pages (from-to)4592-4602
Number of pages11
JournalJournal of Molecular Biology
Volume430
Issue number22
Publication statusPublished - 26 Oct 2018
Peer-reviewedYes

External IDs

WOS 000449242300012
Scopus 85050859036
ORCID /0000-0002-6209-2364/work/142237685

Keywords

Keywords

  • ATP-dependent proteases, conformational dynamics, vesicle encapsulation, protein degradation, single-molecule FRET, HEREDITARY SPASTIC PARAPLEGIA, MITOCHONDRIAL QUALITY-CONTROL, CONFORMATIONAL-CHANGES, PROTEOLYTIC MACHINES, BROWNIAN MOTOR, MOLECULE, TRANSLOCATION, DEGRADATION, MECHANISMS, OPERATION