Structure-function studies on three members of the haloacid dehalogenase (HAD) superfamily of enzymes

Abstract

This chapter provides a general introduction to phosphate monoester hydrolysis, the stereochemistry and mechanism of the reaction and the use of metal ions. It discusses several phosphatases with special emphasis on enzymes belonging to the haloacid dehalogenase (HAD) superfamily, members of which are involved in diverse metabolic processes in the cell. Features that form the basis of classifying this superfamily into several subclasses are discussed. A brief survey of available literature on HAD superfamily is also included. Further, the chapter elaborates on 5'-nucleotidases, their classification and importance in cellular metabolism. The chapter concludes with an account on current understanding about HAD superfamily members and 5'-nucleotidases. Legionella pneumophila IMP/GMP specific cytosolic 5'-nucleotidase (cN-II), Plasmodium falciparum IMP-specific 5'- nucleotidase (ISN1) and a broad specificity phosphatase from Plasmodium vivax, all three being members of HAD superfamily, form the theme of studies reported in this thesis.