Bl. De Groot et al., Conformational changes in the chaperonin GroEL: New insights into the allosteric mechanism, J MOL BIOL, 286(4), 1999, pp. 1241-1249
Conformational changes are known to play a crucial role in the function of
the bacterial GroE chaperonin system. Here, results are presented from an e
ssential dynamics analysis of known experimental structures and from comput
er simulations of GroEL using the CONCOORD method. The results indicate a p
ossible direct form of inter-ring communication associated with internal fl
uctuations in the nucleotide-binding domains upon nucleotide and GroES bind
ing that are involved in the allosteric mechanism of GroEL. At the level of
conformational transitions in entire GroEL rings, nucleotide-induced struc
tural changes were found to be distinct and in principle uncoupled from cha
nges occurring upon GroES binding. However, a coupling is found between nuc
leotide-induced conformational changes and GroES-mediated transitions, but
only in simulations of GroEL double rings, and not in simulations of single
rings. This provides another explanation for the fact that GroEL functions
a double ring system. (C) 1999 Academic Press.