Open AccessCloning, expression, purification, crystallization and preliminary crystallographic analysis of NifH2 from Methanocaldococcus jannaschii
Author(s) -
Huang Kai,
Ma Jinming,
Yuan Ye,
Gao Yongxiang
Publication year - 2011
Publication title -
acta crystallographica section f
Language(s) - English
Resource type - Journals
ISSN - 1744-3091
DOI - 10.1107/s1744309110048104
Subject(s) - nitrogenase , heterotetramer , azotobacter vinelandii , nitrogen fixation , crystallization , biochemistry , azotobacter , biology , escherichia coli , cloning (programming) , crystallography , chemistry , protein subunit , nitrogen , gene , bacteria , genetics , organic chemistry , computer science , programming language
Nitrogenases are protein complexes that are only found in Azotobacter and are required for biological nitrogen fixation. They are made up of a nitrogenase, which is a NifD 2 /NifK 2 heterotetramer, and a nitrogenase reductase, which is a homodimer of NifH. Many homologues of nitrogenase have been found in various non‐nitrogen‐fixing prokaryotes; in particular, they are found in all known methanogens. This indicates that these homologues may play a role in methane production. Here, the cloning of NifH2, a homologue of the NifH nitrogenase component, from Methanocaldococcus jannaschii ( Mj NifH2) and its expression in Escherichia coli with a polyhistidine tag, purification and crystallization are described. Mj NifH2 crystals were obtained by the hanging‐drop vapour‐diffusion method and diffracted to a resolution limit of 2.85 Å. The crystals belonged to space group P 2, with unit‐cell parameters a = 64.01, b = 94.38, c = 98.08 Å, α = γ = 90, β = 98.85°.