Scheme of the arginase pathway and the arginine decarboxylase pathway.

<p>In <i>Bacillus subtilis</i>, the first reaction of the arginase pathway, the formation of ornithine (Orn), is catalyzed by arginase (<i>rocF</i>). RocD, an ornithine aminotransferase, utilizes ornithine to form glutamate semialdehyde (GSA) or pyrroline-5-carboxylate (P5C). P5C is the substrate of RocA, a pyrroline-5-carboxylate dehydrogenase, which produces glutamate (Glu). In <i>Yersinia pestis</i>, an arginine decarboxylase (<i>speA</i>) forms agmatine (Agma). Agma is further degraded to N-carbamoylputrescine (CP) and putrescine (Put) by <i>aguA</i>, <i>aguB</i>, and <i>speB</i>. The genome of Mtb includes homologues for the arginase pathway (<i>rocD</i>, <i>rocA</i>) and the arginine decarboxylase pathway (<i>speA / adi</i>).