Allosteric control by ATP of non-folded protein binding to GroEL

Ofer Yifrach, Amnon Horovitz

Research output: Contribution to journalEditorial

100 Scopus citations


Co-operativity in ATP hydrolysis by GroEL can be described by a model in which each ring of GroEL is in equilibrium between a low (T) and high (R) affinity state for ATP. According to this model, the GroEL double-ring is in equilibrium between three states: TT, TR and RR. In order to find out which states bind non-folded proteins, we measured the co-operativity in ATP hydrolysis by GroEL in the absence and presence of non-folded α-lactalbumin, under equilibrium conditions between GroEL and the non-folded protein. The non-folded protein is found to bind preferentially the T state of GroEL rings and to stimulate the ATPase activity of GroEL by (1) a direct effect on GroEL rings in the T state and (2) a shift in the equilibrium from the RR state toward the more active TR state. The coupling between co-operativity in ATP hydrolysis by GroEL and protein substrate binding and release by this molecular chaperone is shown.

Original languageEnglish
Pages (from-to)356-361
Number of pages6
JournalJournal of Molecular Biology
Issue number3
StatePublished - 26 Jan 1996
Externally publishedYes


  • Allosteric mechanisms
  • Co-operativity
  • Molecular chaperones
  • Protein folding
  • α-lactalbumin

ASJC Scopus subject areas

  • Structural Biology
  • Molecular Biology


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