2JT4:
reference: Structural Basis for Ubiquitin Recognition by SH3 Domains., He Y, Hicke L, Radhakrishnan I, J Mol Biol. 2007 Oct 12;373(1):190-6. Epub 2007 Aug 17. PMID: 17765920

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