Crystalline alcohol dehydrogenases from the mesophilic bacterium Clostridium beijerinckii and the thermophilic bacterium Thermoanaerobium brockii: preparation, characterization and molecular symmetry

Two tetrameric NADP⁺-dependent bacterial secondary alcohol dehydrogenases have been crystallized in the apo- and the holo-enzyme forms. Crystals of the holo-enzyme from the mesophilic Clostridium beijerinckii (NCBAD) belong to space group P2₁2₁2₁ with unit-cell dimensions a = 90.5, b = 127.9, c = 151.4 Å. Crystals of the apo-enzyme (CBAD) belong to the same space group with unit-cell dimensions a = 80.4, b = 102.3, c = 193.5 Å. Crystals of the holo-enzyme from the thermophilic Thermoanaerobium brockii (NTBAD) belong to space group P6₁₍₅₎ (a = b = 80.6, c = 400.7 Å). Crystals of the apo-form of TBAD (point mutant GI98D) belong to space group P2₁ with cell dimensions a = 123.0, b = 84.8, c = 160.4 Å β = 99.5°. Crystals of CBAD, NCBAD and NTBAD contain one tetramer per asymmetric unit. They diffract to 2.0 Å resolution at liquid nitrogen temperature. Crystals of TBAD(GI98D) have two tetramers per asymmetric unit and diffract to 2.7 Å at 276 K. Self-rotation analysis shows that both enzymes are tetramers of 222 symmetry.