Arg305 of Streptomycesl-glutamate oxidase plays a crucial role for substrate recognition

► Arg305 of l-glutamate oxidase (LGOX) is associated with substrate recognition. ► The substrate specificity of LGOX is changed by the mutation of Arg305. ► Substitution of Arg305 with Leu results in alteration of LGOX to l-histidine oxidase.