Author(s):
Coelho, Catarina 
; J. Gonzaléz, Pablo ; Trincão, José ; Carvalho, Ana L. ; Najmudin, Shabir ; Moura, José J. G. ; Hettman, Thomas ; Dieckman, Stephan ; Moura, Isabel ; Romão, Maria J.
Date: 2007
Persistent ID: http://hdl.handle.net/10362/7047
Origin: Repositório Institucional da UNL
Description
Acta Cryst. (2007). F63, 516–519 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-haem 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 A ° 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 A ° , ß = 100.7°, space group C2, and one heterodimer is present per asymmetric unit.
