pubmed:abstractText |
The incubation of chaperonins cpn60 (GroEL) and cpn10 (GroES) from E. coli in the presence of Mg-ATP and KCl generates the formation, as revealed by electron microscopy, of GroEL-GroES complexes with a symmetrical shape in which one toroidal GroES oligomer is bound to each end of the tetradecameric GroEL aggregate (1:2 GroEL:GroES oligomer molar ratio). The symmetrical complexes are not observed in the presence of ADP or the non-hydrolyzable ATP analog, ATP gamma S, where only asymmetrical complexes (1:1 GroEL:GroES oligomer molar ratio) are formed. These results suggest that ATP hydrolysis is required for the formation of symmetrical complexes.
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