D-inositol-3-phosphate glycosyltransferase (, mycothiol glycosyltransferases, MshA) is an enzyme with systematic name UDP-N-acetyl-D-glucosamine:1D-myo-inositol 3-phosphate alpha-D-glycosyltransferase. This enzyme catalyses the following chemical reaction
This enzyme catalyses the first dedicated reaction in the biosynthesis of mycothiol.