1NBE:
reference: A single mutation in the regulatory chain of Escherichia coli aspartate transcarbamoylase results in an extreme T-state structure., Williams MK, Stec B, Kantrowitz ER, J Mol Biol 1998 Aug 7;281(1):121-34. PMID: 9680480

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