The periplasmic nitrate reductase from Cupriavidus necator (also known as Ralstonia eutropha) is a heterodimer that is able to reduce nitrate to nitrite. It comprises a 91 kDa catalytic subunit (NapA) and a 17 kDa subunit (NapB) that is involved in electron transfer. The larger subunit contains a molybdenum active site with a bis-molybdopterin guanine dinucleotide cofactor as well as one [4Fe-4S] cluster, while the small subunit is a di-haemc c-type cytochrome. Crystals of the oxidized form of this enzyme were obtained using polyethylene glycol 3350 as precipitant. A single crystal grown at the High Throughput Crystallization Laboratory of the EMBL in Grenoble diffracted to beyond 1.5 angstrom at the ESRF (ID14-1), which is the highest resolution reported to date for a nitrate reductase. The unit- cell parameters are a = 142.2, b = 82.4, c = 96.8 angstrom, beta = 100.7 degrees, space group C2, and one heterodimer is present per asymmetric unit.
|Journal||Acta Crystallographica Section F: Structural Biology and Crystallization Communications|
|Publication status||Published - 1 Jan 2007|