3CSU:
reference: Assessment of the allosteric mechanism of aspartate transcarbamoylase based on the crystalline structure of the unregulated catalytic subunit., Beernink PT, Endrizzi JA, Alber T, Schachman HK, Proc Natl Acad Sci U S A 1999 May 11;96(10):5388-93. PMID: 10318893

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