Structural and functional conversion of molecular chaperone ClpB from the gram-positive halophilic lactic acid bacterium Tetragenococcus halophilus mediated by ATP and stress.

ABSTRACT: In this study, we report the purification, initial structural characterization, and functional analysis of the molecular chaperone ClpB from the gram-positive, halophilic lactic acid bacterium Tetragenococcus halophilus. A recombinant T. halophilus ClpB (ClpB(Tha)) was overexpressed in Escherichia coli and purified by affinity chromatography, hydroxyapatite chromatography, and gel filtration chromatography. As demonstrated by gel filtration chromatography, chemical cross-linking with glutaraldehyde, and electron microscopy, ClpB(Tha) forms a homohexameric single-ring structure in the presence of ATP under nonstress conditions. However, under stress conditions, such as high-temperature (>45 degrees C) and high-salt concentrations (>1 M KCl), it dissociated into dimers and monomers, regardle

SUBMITTER: Sugimoto S 

PROVIDER: S-EPMC1698206 | biostudies-literature | 2006 Dec

REPOSITORIES: biostudies-literature