This invention relates generally to enzymes, polynucleotides encoding the enzymes, the use of such polynucleotides and polypeptides and more specifically to enzymes having isomerase activity, e.g., racemase activity, e.g., amino acid racemase activity, alanine racemase activity, and/or epimerase activity, and/or catalyze the re¬ arrangement of atoms within a molecule, catalyze the conversion of one isomer into another, catalyze the conversion of an optically active substrate into a raceme, which is optically inactive, catalyze the interconversion of substrate enantiomers, catalyze the stereochemical inversion around the asymmetric carbon atom in a substrate having only one center of asymmetry, catalyze the stereochemical inversion of the configuration around an asymmetric carbon atom in a substrate having more than one asymmetric center, and/or catalyze the racemization of amino acids. Thus, the invention provides enzymes, compositions, methods for production of pharmaceutical compositions, pharmaceutical intermediates, antibiotics, sweeteners, peptide enzymes, peptide hormones, fuel and fuel additive compositions, foods and food additives, beverage and beverage additives, feeds and feed additives, drugs and drug additives, dietary supplements, textiles, wood, paper, pulp, and detergents comprising the polypeptides or polynucleotides in accordance with the invention.