Characterization of a functional GroEL14(GroES7)2 chaperonin hetero-oligomer

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Science  29 Jul 1994:
Vol. 265, Issue 5172, pp. 653-656
DOI: 10.1126/science.7913553


Chaperonins GroEL and GroES form two types of hetero-oligomers in vitro that can mediate the folding of proteins. Chemical cross-linking and electron microscopy showed that in the presence of adenosine triphosphate (ATP), two GroES7 rings can successively bind a single GroEL14 core oligomer. The symmetric GroEL14(GroES7)2 chaperonin, whose central cavity appears obstructed by two GroES7 rings, can nonetheless stably bind and assist the ATP-dependent refolding of RuBisCO enzyme. Thus, unfolded proteins first bind and possibly fold on the external envelope of the chaperonin hetero-oligomer.