Crystal structure of dibenzothiophene sulfone monooxygenase BdsA from Bacillus subtilis WU-S2B

The dibenzothiophene (DBT) sulfone monooxygenase BdsA from Bacillus subtilis WU-S2B catalyzes the conversion of DBT sulfone to 2'-hydroxybiphenyl 2-sulfinate. We report the crystal structures of BdsA at a resolution of 2.80 angstrom. BdsA exists as a homotetramer with a dimer-of-dimers configuration in the crystal, and the interaction between E288 and R296 in BdsA is important for tetramer formation. A structural comparison with homologous proteins shows that the orientation and location of the alpha 9-alpha 12 helices in BdsA are closer to those of the closed form than those of the open form in the EDTA monooxygenase EmoA. (C) 2017 Wiley Periodicals, Inc.