Crystallisation and crystallographic investigations of cod alcohol dehydrogenase class I and class III enzymes.

Cod liver alcohol dehydrogenase of class-hybrid properties has been crystallized as an NAD(+)-pyrazole complex in the monoclinic space group P2(1) with cell dimensions a = 103.3 A, b = 47.4 A, c = 80.7 A, beta = 104.6 degrees, and with one dimer in the asymmetric unit. The position of the dimer molecule in the crystal was determined by molecular replacement methods at 3.0 A resolution. The successful search model was the poly-alanine structure of the horse enzyme. Side chains were then replaced according to the amino acid sequence of the cod enzyme, and the structure has been refined at 2.8 A to an R-factor of 0.26. Cod liver class III alcohol dehydrogenase crystallizes in the monoclinic space group C2 with cell dimensions a = 127.5 A, b = 76.6 A, c = 93.4 A, beta = 99.4 degrees and with probably one dimer in the asymmetric unit.