The Spf1p P5A-ATPase “arm-like” domain is not essential for ATP hydrolysis but its deletion impairs autophosphorylation

P5B-ATPases in the mammalian polyamine transport system and their role in disease

“…of the arm extension is unknown, Grenon et. al demonstrated that its deletion in Spf1 leads to impaired phosphoenzyme formation proportionate to the ATPase activity suggesting that the arm domain is not essential for, but facilitates, ATP hydrolysis [95].…”