<i>In Silico</i> Site-Directed Mutagenesis of Ser¹¹ and Lys¹⁰⁷ on the Predicted 3D Structure of glutathione s-transferase from <i>Acidovoras sp.</i> KKS102

Abstract

Bacterial glutathione s-transferases (GSTs) are known to have variety of functions in detoxification processes. It is familiar that this detoxification ability is achieved through the attack of the thiolate form of glutathione on the electrophilic centres of toxic compounds. Indeed, cytosolic glutathione s-tranferase from Acidovorax sp. KKS102 is now known to have a dehalogenation function. However, little is known about the specific amino
acids involved in this catalytic process. In this study, we investigated the effect of in silico site-directed mutagenesis of the evolutionarily conserved amino acids, Ser11 and Lys107, on the theoretical 3D structure of GST from Acidovorax sp. KKS102 (GST-KKS102) using Deep View/Swiss-Pdb Viewer. The substitution of Ser¹¹, with aromatic amino acids, Tyr, Phe and Trp and positively charged amino acids, Arg, His and lys produced the greatest effect on the stability of the 3D structure of GST-KKS102. Indeed, at Lys¹⁰⁷ position, substitution with nonpolar amino acids, Pro and Gly produced the highest structural stability effect on the theoretical 3D structure of the GST-KKS102. This in silico analysis suggests that Deep View rotamer scores could aid in planning in vitro site-directed mutagenesis studies in protein engineering.

Keywords: Glutathione s-transferase, Acidovoras sp. KKS102, Site-directed mutagenesis, 3D structure, Ser¹¹, Lys¹⁰⁷