User Manual Privacy Policy Disclaimer Contact us
  Advanced SearchBrowse




Journal Article

ATP-induced structural change of the thermosome is temperature-dependent

There are no MPG-Authors available
External Ressource
No external resources are shared
Fulltext (public)
There are no public fulltexts stored in PuRe
Supplementary Material (public)
There is no public supplementary material available

Gutsche, I., Holzinger, J., Rauh, N., Baumeister, W., & May, R. P. (2001). ATP-induced structural change of the thermosome is temperature-dependent. Journal of Structural Biology, 135(2), 139-146.

Cite as: http://hdl.handle.net/11858/00-001M-0000-0010-712C-4
Protein folding by chaperonins is powered by ATP binding and hydrolysis. ATPase activity drives the folding machine through a series of conformational rearrangements, extensively described for the group I chaperonin GroEL from Escherichia coli but still poorly understood for the group II chaperonins. The latter-archaeal thermosome and eukaryotic TMUCCT-function independently of a GroES-like cochaperonin and are proposed to rely on protrusions of their own apical domains for opening and closure in an ATP-controlled fashion. Here we use small-angle neutron scattering to analyze structural changes of the recombinant a-only and the native alpha beta -thermosome from Thermoplasma acidophilum upon their ATPase cycling in solution. We show that specific high-salt conditions, but not the presence of MgATP alone, induce formation of higher order thermosome aggregates. The mechanism of the open-closed transition of the thermosome is strongly temperature-dependent. ATP binding to the chaperonin appears to be a two-step process: at lower temperatures an open state of the ATP-thermosome is predominant, whereas heating to physiological temperatures induces its switching to a closed state. Our data reveal an analogy between the ATPase cycles of the two groups of chaperonins and enable us to put forward a model of thermosome action. (C) 2001 Academic Press. [References: 24]