4R2N:
reference: Crystal structures of Mycobacterium tuberculosis HspAT and ArAT reveal structural basis of their distinct substrate specificities., Nasir N, Anant A, Vyas R, Biswal BK, Sci Rep. 2016 Jan 7;6:18880. doi: 10.1038/srep18880. PMID: 26738801

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