Figure 4.

Mutational analysis of important residues of RhGmaS that may participate in binding substrate and catalysis.A, the enzymatic activities of WT RhGmaS and its mutants. The activity of WT RhGmaS is taken as 100%. Residues involved in binding ATP, MMA, Mg²⁺, and glutamate are marked with black triangles, squares, dots, and stars, respectively. Red pentagons indicate the catalytic residues of RhGmaS. The error bar represents SD of triplicate experiments. B, CD spectra of WT RhGmaS and its mutants. MMA, monomethylamine; RhGmaS, GmaS from Rhodovulum sp. 12E13; CD, circular-dichroism.