The folding cycle in the GroES-GroEL complex of E. coli utilizes the following sequence:
A.ATP binding to GroEL
B.GroES dissociates from the complex
C.Partially folded protein hydrophobic residues bind GroEL
D.GroES is recruited to GroEL
E.GroES promotes ATP hydrolysis and α-subunits undergo a conformational change that buries the hydrophobic patches
A) A, B, C, D, E
B) B, A, C, D, E
C) C, D, A, E, B
D) C, A, D, E, B
E) D, C, E, A, B

Question

Quizplus · Accepted Answer

This sequence is consistent with the "football" model of the GroES-GroEL folding cycle, which has been extensively studied in E. coli. The sequence begins with binding of ATP to GroEL (A), followed by binding of a partially folded protein to hydrophobic residues on GroEL (C). This step is crucial, as it allows the protein to be properly positioned for folding inside the cavity of the GroEL complex. Once the partially folded protein is bound, GroES is recruited to GroEL (D), triggering ATP hydrolysis and a conformational change that buries the hydrophobic patches (E). Finally, GroES dissociates from the complex (B), allowing the folded protein to be released.

The Folding Cycle in the GroES-GroEL Complex of E