Reformulation of an extant ATPase active site to mimic ancestral GTPase activity reveals a nucleotide base requirement for function oleh Taylor B Updegrove, Jailynn Harke, Vivek Anantharaman, Jin Yang, Nikhil Gopalan, Di Wu, Grzegorz Piszczek, David M Stevenson, Daniel Amador-Noguez, Jue D Wang, L Aravind, Kumaran S Ramamurthi