Nucleotide‐dependent oligomerization of C1pB from Escherichia coli

作者：Michal Žółkiewski, Martin Kessel, Ann Ginsburg, Michael R. Maurizi · 发表于：Protein Science · 年份：1999 · DOI：10.1110/ps.8.9.1899 · 被引用次数：80 · 研究领域：Heat shock proteins research、Enzyme Structure and Function、Protein Structure and Dynamics

Self-association of ClpB (a mixture of 95- and 80-kDa subunits) has been studied with gel filtration chromatography, analytical ultracentrifugation, and electron microscopy. Monomeric ClpB predominates at low protein concentration (0.07 mg/mL), while an oligomeric form is highly populated at >4 mg/mL. The oligomer formation is enhanced in the presence of 2 mM ATP or adenosine 5'-O-thiotriphosphate (ATPgammaS). In contrast, 2 mM ADP inhibits full oligomerization of ClpB. The apparent size of the ATP- or ATPgammaS-induced oligomer, as determined by gel filtration, sedimentation velocity and electron microscopy image averaging, and the molecular weight, as determined by sedimentation equilibrium, are consistent with those of a ClpB hexamer. These results indicate that the oligomerization reactions of ClpB are similar to those of other Hsp100 proteins.