PNAS97(20),10723–10728(2000), DOI10.1073/pnas.97.20.10723. Primary indexed Abstract and text: bovine XDH2.1Å and XO2.5Å structures, conformational change near FAD affecting NAD access. Original first-author byline C. Enroth retained; no guessed full name. Primary text pmc.ncbi.nlm.nih.gov/articles/PMC27090/ and original structure deposits1FO4/1FIQ; direct fetch challenged, indexed primary content verified.