Human and Mouse Hypoxanthine-Guanine Phosphoribosyltransferase: Dimers and Tetramers

Abstract
Human and mouse hypoxanthine-guanine phosphoribosyltransferase subunits combine to form an active heteropolymer. Dimers form the basic subunit structure of the enzymes, yet the dimers can readily associate to form tetramers. The equilibrium between dimers and tetramers is significantly influenced by the ionic strength of the enzyme solvent.