1SFT:
reference: Determination of the structure of alanine racemase from Bacillus stearothermophilus at 1.9-A resolution., Shaw JP, Petsko GA, Ringe D, Biochemistry 1997 Feb 11;36(6):1329-42. PMID: 9063881

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