4HFQ:
reference: A UDP-X diphosphatase from Streptococcus pneumoniae hydrolyzes precursors of peptidoglycan biosynthesis., Duong-Ly KC, Woo HN, Dunn CA, Xu W, Babic A, Bessman MJ, Amzel LM, Gabelli SB, PLoS One. 2013 May 15;8(5):e64241. doi: 10.1371/journal.pone.0064241. Print 2013. PMID: 23691178

This OCA Structure page
uses Jmol, developed by the Jmol Development Team (documentation).