Catalyzes the formation of isethionate from 2-sulfoacetaldehyde in the deaminative pathway of taurine. Constitutively expressed enzyme that only mediates a small part of the activity observed in taurine-grown cells. 2-hydroxyethane-1-sulfonate + NADP(+) = H(+) + NADPH + sulfoacetaldehyde Organosulfur degradation. Homodimer and heterotetramer. Constitutively expressed. Belongs to the short-chain dehydrogenases/reductases (SDR) family.