Mechanism of Allosteric Activation of Samhd1 by Dgtp

The dNTPase SAMHD1 inhibits infection by HIV-1 and other retroviruses. In the presence of dGTP, the enzyme forms tetramers and becomes active, a process that is now elucidated by structural, biochemical and cellular analyses of human SAMHD1. Binding of dGTP to four allosteric sites promotes tetramerization and induces a conformational change in the substrate-binding pocket to activate the enzyme.