CotA of <i>Bacillus subtilis</i> Is a Copper-Dependent Laccase

TLDR

CotA is a spore coat protein of *Bacillus subtilis* that shares structural features with multicopper oxidases such as manganese oxidases and laccases. Although *B.

Abstract

ABSTRACT The spore coat protein CotA of Bacillus subtilis displays similarities with multicopper oxidases, including manganese oxidases and laccases. B. subtilis is able to oxidize manganese, but neither CotA nor other sporulation proteins are involved. We demonstrate that CotA is a laccase. Syringaldazine, a specific substrate of laccases, reacted with wild-type spores but not with Δ cotA spores. CotA may participate in the biosynthesis of the brown spore pigment, which appears to be a melanin-like product and to protect against UV light.