Open AccessHeterodimeric nitrate reductase (NapAB) from Cupriavidus necator H16: purification, crystallization and preliminary X‐ray analysis
Author(s) -
Coelho Catarina,
González Pablo J.,
Trincão José,
Carvalho Ana L.,
Najmudin Shabir,
Hettman Thomas,
Dieckman Stephan,
Moura José J. G.,
Moura Isabel,
Romão Maria J.
Publication year - 2007
Publication title -
acta crystallographica section f
Language(s) - English
Resource type - Journals
ISSN - 1744-3091
DOI - 10.1107/s1744309107022129
Subject(s) - cupriavidus necator , crystallization , nitrate reductase , chemistry , nitrate , poly 3 hydroxybutyrate , nuclear chemistry , materials science , biochemistry , bacteria , biology , organic chemistry , polyhydroxyalkanoates , genetics
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 Å 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 Å, β = 100.7°, space group C 2, and one heterodimer is present per asymmetric unit.