Journal of
Biophysics and Structural Biology

  • Abbreviation: J. Biophys. Struct. Biol.
  • Language: English
  • ISSN: 2141-2200
  • DOI: 10.5897/JBSB
  • Start Year: 2009
  • Published Articles: 25

Full Length Research Paper

Crystal structure of the allosteric-defective chaperonin GroELE434K mutant

Aintzane Cabo-Bilbao1, Ariel E. Mechaly2, Jon Agirre1, Silvia Spinelli3, Begoña Sot4, Arturo Muga1 and Diego M.A. Guérin1*
1Unidad de Biofísica (UBF, CSIC-UPV/EHU) and Departamento de Bioquímica y Biología Molecular, UPV/EHU. Barrio Sarriena s/n, E-48940, Leioa, Spain. 2Unité de Biochimie Structurale, Institut Pasteur, 25 rue du Dr. Roux, F-75724 Paris, France. 3AFMB-CNRS, UMR 6098, 163, Av. de Luminy, 13288 Marseille Cedex 09, France. 4Centro Nacional de Biotecnología, CSIC, Campus de la Universidad Autónoma de Madrid, Darwin, 3, 28049 Madrid, Spain.
Email: [email protected]

  •  Accepted: 25 August 2011
  •  Published: 11 November 2011

Abstract

The chaperonin GroEL adopts a double-ring structure with various modes of allosteric communication. The simultaneous positive intra-ring and negative inter-ring cooperativities allow alternating functionality of the folding cavities in both protein rings. Mutation of glutamic acid 434 (located at the ring interface), to lysine alters the negative inter-ring cooperativity. The crystal structure of the mutant chaperonin GroELE434K has been determined at low-resolution (4.5 Å) and has been compared to the wild-type GroEL and the allosteric-defective GroELE461K mutant structures. Despite the allosteric-defective behavior of the GroELE434Kmutant, its structure remains strikingly similar to that of the wild-type GroEL.

 

Key words: Chaperonin, GroEL, cooperativity, twinning, low-resolution refinement.