Structure at 2.8 Â resolution of F1-ATPase from bovine heart mitochondria.

Walker used X-ray crystallography to determine the structure of ATP synthase (ATPase or adenosine triphosphatase). In 1997 Walker shared the Nobel Prize in Chemistry with Paul Boyer and Jens C. Skou “for their elucidation of the enzymatic mechanism underlying the synthesis of adenosine triphosphate (ATP).”

(Thanks to Juan Weiss for this reference and its interpretation.)