GroEL

A homo-tetradecameric chaperonin, composed of 57 kDa subunits of three functional domains each, arranged as a hollow cylinder of two stacked rings with seven-fold symmetry in E. coli. It binds to the smaller GroES molecule. GroEL and GroES are encoded in the same operon of E. coli (see Fig. G64). Although the information for folding resides in the primary structure of proteins, the GroEL–GroES complex facilitates the realization of this potential. In E. coli, ∼250 proteins interact with GroEL but most of these can utilize the upstream chaperone trigger factor and DnaK for folding (Kerner MJ et al 2005 Cell 122:209). chaperone, chaperonin, protein folding, DnaK, trigger factor; Feltham JL, Gierash LM 2000 Cell 100:193; Farr GW et al 2000 Cell 100:561.

Figure G64.

GroES and GroEL structure