Discuss the structure of the chaperonin GroESGroEL complex found in E. coli. What will be an ...

ANSWER: In the GroESGroEL complex, GroEL is a protein made of two stacked seven-membered rings of 60-kD subunits that form a cylindrical 14 oligomer 15 nm high and 14 nm wide. Each GroEL ring has a 5-nm central cavity where folding can take place. This cavity can accommodate proteins up to 60 kD in size. GroES, sometimes referred to as a co-chaperonin, consists of a single seven-membered ring of 10-kD subunits that sits like a dome on one end of GroEL. The end of GroEL where GroES is sitting is referred to as the apical end. Each GroEL subunit has two structural domains: an equatorial domain that binds ATP and interacts with neighbors in the other 7 ring and an apical domain with hydrophobic residues that can interact with hydrophobic regions on partially folded proteins.