title: A haloarchaeal ferredoxin electron donor that plays an essential role in nitrate assimilation.
abstract: In the absence of ammonium, many organisms, including the halophilic archaeon Haloferax volcanii DS2 (DM3757), may assimilate inorganic nitrogen from nitrate or nitrite, using a ferredoxin-dependent assimilatory NO₃⁻/NO₂⁻ reductase pathway. The small acidic ferredoxin Hv-Fd plays an essential role in the electron transfer cascade required for assimilatory nitrate and nitrite reduction by the cytoplasmic NarB- and NirA-type reductases respectively. UV-visible absorbance and EPR spectroscopic characterization of purified Hv-Fd demonstrate that this protein binds a single [2Fe-2S] cluster, and potentiometric titration reveals that the cluster shares similar redox properties with those present in plant-type ferredoxins.
authors: División de Bioquímica y Biología Molecular, Facultad de Ciencias, Universidad de Alicante, Campus de San Vicente del Raspeig, 03080 Alicante, Spain.
authors: Basilio
authors: B
authors: Zafrilla
authors: Rosa María
authors: RM
authors: Martínez-Espinosa
authors: María José
authors: MJ
authors: Bonete
authors: Julea N
authors: JN
authors: Butt
authors: David J
authors: DJ
authors: Richardson
authors: Andrew J
authors: AJ
authors: Gates
mesh_terms: D000595:Amino Acid Sequence; D004583:Electrons; D005288:Ferredoxins / Q000737:chemistry / Q000378:metabolism*; D019622:Haloferax volcanii / Q000378:metabolism*; D008969:Molecular Sequence Data; D009566:Nitrates / Q000378:metabolism*; D009573:Nitrites / Q000378:metabolism; D013057:Spectrum Analysis
chemical_list: D005288:Ferredoxins; D009566:Nitrates; D009573:Nitrites