4JPX:
reference: An additional substrate binding site in a bacterial phenylalanine hydroxylase., Ronau JA, Paul LN, Fuchs JE, Corn IR, Wagner KT, Liedl KR, Abu-Omar MM, Das C, Eur Biophys J. 2013 Jul 17. PMID: 23860686

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