Evaluation of the stability of an SR398/GroES chaperonin complex

The stability of an SR398/GroES chaperonin complex was examined. As was expected, based on the finding of previous studies, the SR398/GroES complex was extremely stable in the presence of an excess amount of free adenosine 5'-[-thio]triphosphate (ATPS) or adenosine 5'-(β,-imido)triphosphate (AMPPNP). However, the complex was not stable in the absence of nucleotides. These results indicate that ATPS and AMPPNP repeatedly associated to and dissociated from the complex in a non-cooperative manner. This nucleotide exchange did not induce the dissociation of GroES and substrate from SR398, suggesting the importance of the cooperative dissociation of nucleotides from the cis-ring to release GroES and substrate proteins in the GroEL/GroES reaction cycle.

Source: Journal of Biochemistry - April 27, 2014 Category: Biochemistry Authors: Ishino, S., Kawata, Y., Ikegami, T., Matsuzaki, K., Hoshino, M. Tags: Regular Papers Source Type: research