Next, coprophyrinogen III is brought back into the mitochondria and converted into protoporphyrinogen IX by coproporphyrinogen oxidase.

然后，粪原Ⅲ被运送回线粒体，并通过粪原化酶转化为原原IX。

Afterwards, hydroxymethylbilane is converted to uroporphyrinogen III and catalyzed to coproporphyrinogen III via uroporphyrinogen III cosynthase and uroporphyrinogen decarboxylase, respectively.

之后，羟甲基胆素通过原III协同合成酶转化为原III，再由原脱羧酶催化为粪原III。

Afterwards, hydroxymethylbilane is converted to Uroporphyrinogen III and catalyzed to coproporphrinogen III, via uroporphyrinogen III co-synphase and uroporphyrinogen decarboxylase respectively.

之后，羟甲基胆色烷转化为原III，并分别通过原Ⅲ共合酶与原脱羧酶催化形成粪原Ⅲ。