Open AccessThe effect of nucleotides and mitochondrial chaperonin 10 on the structure and chaperone activity of mitochondrial chaperonin 60
Author(s) -
LevyRimler Galit,
Viitanen Paul,
Weiss Celeste,
Sharkia Rajach,
Greenberg Anat,
Niv Adina,
Lustig Ariel,
Delarea Yacov,
Azem Abdussalam
Publication year - 2001
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1046/j.1432-1327.2001.02243.x
Subject(s) - chaperonin , atp–adp translocase , atp hydrolysis , chaperone (clinical) , groel , biology , biochemistry , nucleotide , protein folding , mitochondrion , biophysics , enzyme , inner mitochondrial membrane , atpase , escherichia coli , gene , medicine , pathology
Mitochondrial chaperonins are necessary for the folding of newly imported and stress‐denatured mitochondrial proteins. The goal of this study was to investigate the structure and function of the mammalian mitochondrial chaperonin system. We present evidence that the 60 kDa chaperonin (mt‐cpn60) exists in solution in dynamic equilibrium between monomers, heptameric single rings and double‐ringed tetradecamers. In the presence of ATP and the 10 kDa cochaperonin (mt‐cpn10), the formation of a double ring is favored. ADP at very high concentrations does not inhibit malate dehydrogenase refolding or ATP hydrolysis by mt‐cpn60 in the presence of mt‐cpn10. We propose that the cis (mt‐cpn60) 14 ·nuleotide·(mt‐cpn10) 7 complex is not a stable species and does not bind ADP effectively at its trans binding site.