Monooxygenase that initiates the degradation of pyrrole-2-carboxylate, which allows Arthrobacter sp. strain Py1 to grow on pyrrole-2-carboxylate as sole carbon, nitrogen, and energy source. To a lesser extent, can also use pyrrole, pyrrole-2-aldehyde, and indole-2-carboxylate as substrate. H(+) + NADH + O2 + pyrrole-2-carboxylate = 5-hydroxypyrrole-2-carboxylate + H2O + NAD(+) Homotrimer.