The effects of mutating Tyr9 and Arg15 on the structure, stability, conformational dynamics and mechanism of GSTA3-3.

Glutathione S-transferase A3-3 is the most catalytically efficient steroid isomerase enzyme known in humans, transforming Δ-androstene-3-17-dione into Δ-androstene-3-17-dione. GSTA3-3 catalyzes this reaction with ten-fold greater efficiency than GSTA1-1, its closest competitor in the Alpha class of GSTs. In order to examine the differences between Alpha class GSTs and to better elucidate the mechanism of GSTA3-3 the roles of Tyr9 and Arg15 were examined.