1XFC:
reference: The 1.9 A crystal structure of alanine racemase from Mycobacterium tuberculosis contains a conserved entryway into the active site., LeMagueres P, Im H, Ebalunode J, Strych U, Benedik MJ, Briggs JM, Kohn H, Krause KL, Biochemistry 2005 Feb 8;44(5):1471-81. PMID: 15683232

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