Catalyzes the racemization of L-alanine to D-alanine, and of L-glutamate to D-glutamate. The activity is low, but likely physiological since W.pipientis wMel lacks canonical alr and murI genes, while D-alanine and D-glutamate are essential components of peptidoglycan. Also displays a vestigial cystathionine beta-lyase (CBL) activity, cleaving cystathionine to homocysteine and pyruvate; however, this reaction seems not to be physiologically relevant since the only met gene in the genome of this obligately intracellular parasitic bacterium is metC, demonstrating that it is a methionine auxotroph. L-alanine = D-alanine L-glutamate = D-glutamate H2O + L,L-cystathionine = L-homocysteine + NH4(+) + pyruvate kcat is 0.001 sec(-1) for cystathionine beta-lyase activity (at pH 8.8 and 37 degrees Celsius). kcat is 2.3 sec(-1) for alanine racemase activity (at pH 8.8 and 37 degrees Celsius). kcat is 0.017 sec(-1) for glutamate racemase activity (at pH 8.0 and 37 degrees Celsius). Cell wall biogenesis; peptidoglycan biosynthesis. Homotetramer; dimer of active dimers. Belongs to the trans-sulfuration enzymes family.