EC Number |
---|
1.6.5.4 | - |
1.6.5.4 | 3D model of Mdar protein contains 21 sheets and 15 helices and 33 loop regions. The active site is comprised of residues Glu39, Glu40, Glu46, Arg47, Pro48, Lys52, Thr122, Asn147, Tyr173, Pro194, Glu195, Arg201, Ile261, Asn264, Asp299, Glu316, His317, Arg322, Phe347 and Tyr348 |
1.6.5.4 | purified recombinant enzyme, immediately after purification by hanging drop vapour diffusion method, 0.005 ml of protein solution containing 10 mg/ml protein, mixed with equal volume of reservoir solution containing 20-25% PEG 6000, 0.1 M CaCl2, 50 mM Tris-HCl, pH 8.0, equilibration against 1 ml reservoir solution, 20°C, 1 week, cryoprotection by 30% glycerol, X-ray diffraction structure determination and analysis at 2.4 A resolution |
1.6.5.4 | structures in the presence of cofactors, NAD+ and NADP+, and complexed with ascorbic acid and isoascorbic acid. The overall structure of MDHAR is similar to other iron-sulfur protein reductases, except for a unique long loop of 63-80 residues, which seems to be essential in forming the active site pocket. Residue Arg320 plays a major substrate binding role, and Tyr349 mediates electron transfer from NAD(P)H to bound substrate via FAD. The enzymatic activity favours NADH as an electron donor over NADPH |
1.6.5.4 | to 1.9 A resolution, space group P41212 with unit-cell parameters a, b 81.89 A, c 120.4 A |