3C1U:
reference: Short strong hydrogen bonds in proteins: a case study of rhamnogalacturonan acetylesterase., Langkilde A, Kristensen SM, Lo Leggio L, Molgaard A, Jensen JH, Houk AR, Navarro Poulsen JC, Kauppinen S, Larsen S, Acta Crystallogr D Biol Crystallogr. 2008 Aug;64(Pt 8):851-63. Epub 2008, Jul 17. PMID: 18645234

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