Crystallization of a flavodoxin involved in nitrogen fixation in Rhodobacter capsulatus

PÉREZ.DORADO, INMACULADA; BORTOLOTTI, ANA; CORTEZ NÉSTOR; HERMOSO, J. A.

Acta Crystallographica F

Año: 2008 vol. F64 p. 375 - 377

Flavodoxins are small electron-transfer proteins that contain one molecule ofnoncovalently bound flavin mononucleotide (FMN). The flavodoxin NifF fromthe photosynthetic bacterium Rhodobacter capsulatus is reduced by oneelectron from ferredoxin/flavodoxin:NADP(H) reductase and was postulatedto be an electron donor to nitrogenase in vivo. NifF was cloned and overexpressedin Escherichia coli, purified and concentrated for crystallization usingthe hanging-drop vapour-diffusion method at 291 K. Crystals grew from amixture of PEG 3350 and PEG 400 at pH 5.5 and belong to the tetragonal spacegroup P41212, with unit-cell parameters a = b = 66.49, c = 121.32 A ¢ª . X-ray datasets have been collected to 2.17 A ¢ª resolution.