Fig 6.

A model for the complex formation of WT and tsf coat proteins with GroEL. The sigmoidal relationship for coat protein binding to GroEL can be explained by the presence of 2 intermediates in the folding of coat protein, [I] and [I*]. The intermediate [I] is present in the on-pathway folding of coat protein, while [I*] is either an intermediate found off-pathway leading toward aggregation or may be an intermediate on the folding pathway, indicated by the presence of the question mark. If GroEL binds to [I*] with higher affinity than to [I], and the concentration of [I*] increases as the coat protein concentration is increased, then a sigmoidal shape to the curve could be expected