2CSA:
reference: Identification and structural determination of the M(3) muscarinic acetylcholine receptor basolateral sorting signal., Iverson HA, Fox D 3rd, Nadler LS, Klevit RE, Nathanson NM, J Biol Chem 2005 Jul 1;280(26):24568-75. Epub 2005 May 2. PMID: 15870063

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