5k9b | pdb_00005k9b

Azotobacter vinelandii Flavodoxin II

spinqualitylabelsall models 5k9b, resolution 1.17Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 5k9b is a 1 chain structure with sequence from Azotobacter vinelandii. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 1.174Å Ligands: FMN, MG Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function FLAV_AZOVI Low-potential electron donor to a number of redox enzymes. NifF is the electron donor to nitrogenase. Publication Abstract from PubMed Azotobacter vinelandii flavodoxin II serves as a physiological reductant of nitrogenase, the enzyme system mediating biological nitrogen fixation. Wildtype A. vinelandii flavodoxin II was electrochemically and crystallographically characterized to better understand the molecular basis for this functional role. The redox properties were monitored on surfactant-modified basal plane graphite electrodes, with two distinct redox couples measured by cyclic voltammetry corresponding to reduction potentials of -483 +/- 1 mV and -187 +/- 9 mV (vs. NHE) in 50 mM potassium phosphate, 150 mM NaCl, pH 7.5. These redox potentials were assigned as the semiquinone/hydroquinone couple and the quinone/semiquinone couple, respectively. This study constitutes one of the first applications of surfactant-modified basal plane graphite electrodes to characterize the redox properties of a flavodoxin, thus providing a novel electrochemical method to study this class of protein. The X-ray crystal structure of the flavodoxin purified from A. vinelandii was solved at 1.17 A resolution. With this structure, the native nitrogenase electron transfer proteins have all been structurally characterized. Docking studies indicate that a common binding site surrounding the Fe-protein [4Fe:4S] cluster mediates complex formation with the redox partners Mo-Fe protein, ferredoxin I, and flavodoxin II. This model supports a mechanistic hypothesis that electron transfer reactions between the Fe-protein and its redox partners are mutually exclusive. This article is protected by copyright. All rights reserved. Electrochemical and Structural Characterization of Azotobacter vinelandii Flavodoxin II.,Segal HM, Spatzal T, Hill MG, Udit AK, Rees DC Protein Sci. 2017 Jul 14. doi: 10.1002/pro.3236. PMID:28710816 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Flavodoxin 3D structures

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