Inside chaperonins

Enzymes assist formation of proper disulfide bonds during folding Isomerization of proline residues can be a rate-limiting step in protein folding Proteins can fold or unfold inside chaperonins GroEL is a cylindrical structure with a... 

Figure 6.11 Schematic diagram of the chaperonin GroEL molecule as a cylinder with 14 subunits arranged in two tings of 7 subunits each. The space occupied by one subunit is red and the hole inside the cylinder is blue.

Once inside a cell the vesicles lose their coats to become endosomes which may then fuse with lysosomes or with Golgi membranes. The removal of a clathrin coat requires ATP as well as the chaperonin Hsp 70 (Chapter 10) and a coat protein called auxilin.568 Triskelion is distorted and displaced from the clathrin cage. The interior of the newly formed endosome is quickly acidified by the action of a proton pump in the vesicle walls.554 569 This sometimes leads to dissociation of enclosed receptors from their ligands and permits recycling of receptors and lipids of the vesicle membranes to the cell surface. This is the case for the low-density lipoprotein receptor.570 571... 

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