The URO-D _like protein superfamily includes bacterial and eukaryotic uroporphyrinogen decarboxylases (URO-D), coenzyme M methyltransferases and other putative bacterial methyltransferases. Uroporphyrinogen decarboxylase (URO-D) decarboxylates the four acetate side chains of uroporphyrinogen III (uro-III) to create coproporphyrinogen III, an important branching point of the tetrapyrrole biosynthetic pathway. The methyltransferases represented here are important for ability of methanogenic organisms to use other compounds than carbon dioxide for reduction to methane.