4J3B:
reference: A naturally variable residue in the S1 subsite of M1-family aminopeptidases modulates catalytic properties and promotes functional specialization., Dalal S, Ragheb DR, Schubot FD, Klemba M, J Biol Chem. 2013 Jul 29. PMID: 23897806

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