Part of the AaxABC system, catalyzes the decarboxylation of L-arginine. The arginine uptake by the bacterium in the macrophage may be a virulence factor against the host innate immune response. H(+) + L-arginine = agmatine + CO2 Binds 1 pyruvoyl group covalently per subunit. Inhibited by argininamide. Optimum pH is 3.4. Thermostable. Retains 48% activity at 50 degrees Celsius, and 13% activity at 100 degrees Celsius. Trimer of an alpha-beta dimer. Belongs to the pyruvoyl-dependent arginine decarboxylase family.