Fig. 1.

(A) The conformational states visited during the chaperonin cycle (for simplicity, only one GroEL ring is shown). Three crystal structures (PDB ID codes 1SVT, 1AON, and 1XCK) have been solved by crystallography to a resolution of 3.0 Å or better. Cryo-EM structures (4AAS and five others) of the R-ATP state around 8.5 Å resolution also exist. The crystal structure of the R-ADP state is reported here. (B) The positions of the interdomain, intrasubunit D83-K327 (red and blue spheres) and interdomain, intersubunit R197-E386 (black and yellow spheres) salt bridges before and after the T to R allosteric transition.