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Structure of the ParM filament at 8.5A resolution.

ABSTRACT: The actin-like protein ParM forms the cytomotive filament of the ParMRC system, a type II plasmid segregation system encoded by Escherichia coli R1 plasmid. We report an 8.5Å resolution reconstruction of the ParM filament, obtained using cryo-electron microscopy. Fitting of the 3D density reconstruction with monomeric crystal structures of ParM provides insights into dynamic instability of ParM filaments. The structural analysis suggests that a ParM conformation, corresponding to a metastable state, is held within the filament by intrafilament contacts. This filament conformation of ParM can be attained only from the ATP-bound state, and induces a change in conformation of the bound nucleotide. The structural analysis also provides a rationale for the observed stimulation of hydrolysis upon polymerisation into the filament.

SUBMITTER: Gayathri P

PROVIDER: S-EPMC3794156 | biostudies-literature | 2013 Oct

REPOSITORIES: biostudies-literature

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Structure of the ParM filament at 8.5Å resolution.

Gayathri Pananghat P Fujii Takashi T Namba Keiichi K Löwe Jan J

Journal of structural biology 20130224 1

The actin-like protein ParM forms the cytomotive filament of the ParMRC system, a type II plasmid segregation system encoded by Escherichia coli R1 plasmid. We report an 8.5Å resolution reconstruction of the ParM filament, obtained using cryo-electron microscopy. Fitting of the 3D density reconstruction with monomeric crystal structures of ParM provides insights into dynamic instability of ParM filaments. The structural analysis suggests that a ParM conformation, corresponding to a metastable st ...[more]

PMID: 23462100

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