FIG 1.

BCDA is a poor inactivator of MtAlr. (A) Currently accepted molecular model of BCDA hydrolysis or covalent adduct formation catalyzed by PLP-dependent enzymes. (B) Representative time course kinetics of pyruvate formation of recombinant EcAlr, BsAlr, and MtAlr (normalized to 1 μM enzyme) in the presence of 1 mM BCDA. Reactions were monitored by observing NADH oxidation upon the production of pyruvate from BCDA via a coupled enzyme assay system (lactate dehydrogenase). (C) Steady-state kinetic and time-dependent inhibition parameters for Alr orthologues with l-alanine and BCDA. Results are the averages ± standard errors of the means (SEM) from at least triplicate data sets. See also Fig. S1 in the supplemental material.