Figure 5.
Mg2+ regulates the stoichiometry of the GroEL–ES complex. (A) Mass spectra shown in (A) and (B) illustrate the effects of Mg2+ concentration on the formation of GroEL14–GroES7 and GroEL14–GroES8 complexes. The solution conditions used (solutions F and G) only differ in concentrations of Mg2+, (A) 500 μM and (B) 25 μM collected at 12K resolution (HCD = 200 V) at 24 °C. The inset in (B) illustrates the resolving power available to assign the GroES bound state of the GroEL as well as the ATP bound state of each GroEL14–GroES7 state.