Catalyzes the third and final step of the '4S' desulfurization pathway that removes covalently bound sulfur from dibenzothiophene (DBT) without breaking carbon-carbon bonds. Oxidizes 2-(2'-hydroxyphenyl)benzene sulphinate (HBPS) to 2-hydroxybiphenyl (HBP) plus sulfite. The rate-limiting step of the '4S' desulfurization pathway. 2'-hydroxybiphenyl-2-sulfinate + H2O = biphenyl-2-ol + H(+) + sulfite Sulfur metabolism; dibenzothiophene degradation. Monomer. Can be used to remove sulfur from polycyclic aromatic sulfur compounds found in gasoline and diesel (biodesulfurization), which are a considerable source of pollution. As the substrates are not very soluble in conventional media, biphasic systems may help improve catalysis. Expression of dszD-dszA-dszB-dszC (cloned in this order) in organic-solvent-tolerant P.putida strain Idaho allows P.putida to grow on 10% p-xylene with DBT as the sole sulfur source. In this P.putida strain 97% of DBT was degraded, 71% of 4,6-dimethyldibenzothiophene and about 50% of 3-methyldibenzothiophene or 4-methyldibenzothiophene was degraded in the presence of 10% p-xylene. Degradation of DBT in the presence of 10% of other organic solvents was tested; when grown in dodecane, cyclohexane or heptanol bacteria metabolized DBT as well as p-xylene, while other organic solvents degraded DBT slightly less well. Belongs to the DszB desulfinase family.