Involved in the biosynthesis of sulfolipids found in thylakoid membranes. Converts UDP-glucose and sulfite to the sulfolipid head group precursor UDP-sulfoquinovose. The sulfite is delivered to the reaction center by the FMN-binding domain of FdGOGAT. H(+) + sulfite + UDP-alpha-D-glucose = H2O + UDP-alpha-D-6-sulfoquinovose Optimum pH is 8.0-8.5. Homodimer. Interacts with FdGOGAT (via FMN-binding domain). The N-terminus is blocked. Belongs to the NAD(P)-dependent epimerase/dehydratase family.