3HP4:
reference: Structure of EstA esterase from psychrotrophic Pseudoalteromonas sp. 643A covalently inhibited by monoethylphosphonate., Brzuszkiewicz A, Nowak E, Dauter Z, Dauter M, Cieslinski H, Dlugolecka A, Kur J, Acta Crystallogr Sect F Struct Biol Cryst Commun. 2009 Sep 1;65(Pt, 9):862-5. Epub 2009 Aug 20. PMID: 19724118

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