2.1.1.76 ? x * 40000, SDS-PAGE 2.1.1.76 ? x * 40066, calculated from amino acid sequence 2.1.1.76 homodimer 2 * 42030, recombinant His6-tagged enzyme, sequence calculation, 2 * 42000, recombinant His6-tagged enzyme, SDS-PAGE 2.1.1.76 monomer 1 * 31000, SDS-PAGE