Meta-Biol

• Pathways

SAMHD1:Zn2+ tetramer (Deoxynucleoside triphosphate triphosphohydrolase SAMHD1, also known as SAM domain and HD domain-containing protein 1) catalyzes the hydrolysis of dNTPs (2'-deoxynucleoside 5'-triphosphates) to form 2'-deoxynucleosides and PPPi (triphosphate) (Goldstone et al. 2011; Powell et al. 2011). The active form of the enzyme is a tetramer with one Zn2+ ion associated with each monomer subunit (Yan et al. 2013; Zhu et al. 2013) localized in the nucleus (Franzolin et al. 2013; Rice et al. 2009). The enzyme is activated by dGTP (Powell et al. 2011).

SAMHD1 activity may play a role in regulating the size of the nuclear pools of dNTPs and dissipating these pools at the end of the S phase of the cell cycle (Franzolin et al. 2013) and it may play a role as well in regulating cellular antiviral responses (Goldstone et al. 2011; Rice et al. 2009).