Flexibility impaired by mutations revealed the multifunctional roles of the loop in glutathione synthetase

Three residues found in the loop which extends from Ile-226 to Arg-241 in the glutathione synthetase from Escherichia coli B were substituted with alanine and valine to restrict its flexibility. The conformational dispersal between open and closed states and the conformational flexibility to the closed state might be prevented by mutations on the loop.