title: Structural and theoretical studies indicate that the cylindrical protease ClpP samples extended and compact conformations.
abstract: The highly conserved ClpP protease consists of two heptameric rings that interact by the interdigitation of an alpha-helix beta strand handle domain motif to form a tetradecameric cylinder. We previously proposed that protease dynamics results in the temporary unstructuring of interacting pairs of handle domains, opening transient equatorial side pores that allow for peptide egress. Here, we report the structure of an Escherichia coli ClpP mutant in which each opposing pair of protomers is linked by a disulfide bond. This structure resembles the compact structures of Streptococcus pneumoniae, Mycobacterium tuberculosis, and Plasmodium falciparum ClpPs, rather than the active, extended structures that have previously been determined for E. coli ClpPs. The structural data, along with normal mode analysis, support a model whereby the ClpP cylinder switches dynamically between an active extended state required for substrate degradation and an inactive compact state allowing peptide product release.
authors.affiliation: Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON N1G 2W1, Canada.
authors.forename: Matthew S
authors.initials: MS
authors.lastname: Kimber
authors.forename: Angela Yeou Hsiung
authors.initials: AY
authors.lastname: Yu
authors.forename: Mikael
authors.initials: M
authors.lastname: Borg
authors.forename: Elisa
authors.initials: E
authors.lastname: Leung
authors.forename: Hue Sun
authors.initials: HS
authors.lastname: Chan
authors.forename: Walid A
authors.initials: WA
authors.lastname: Houry
mesh_terms: D000595:Amino Acid Sequence; D018360:Crystallography, X-Ray; D049071:Endopeptidase Clp / Q000737:chemistry* / Q000235:genetics; D029968:Escherichia coli Proteins / Q000737:chemistry* / Q000235:genetics; D008956:Models, Chemical; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D011487:Protein Conformation; D021122:Protein Subunits / Q000737:chemistry; D013045:Species Specificity; D014461:Ultracentrifugation
chemical_list: D029968:Escherichia coli Proteins; D021122:Protein Subunits; C483572:ClpP protease, E coli; D049071:Endopeptidase Clp