Crystallization and preliminary crystallographic studies of the mitochondrial F₁-ATPase from the yeast Saccharomyces cerevisiae

A genetically modified (His₆-tagged) form of the mitochondrial F₁-­ATPase (MW = 370 kDa) has been purified from the yeast Saccharomyces cerevisiae and crystallized in the presence of polythelene glycol (PEG) 6000 as a precipitant, 1 mM NiCl₂, 1 mM Mg AMP-PNP and 50 µM Mg ADP. X-ray diffraction data were obtained on three separate occasions using synchrotron radiation, with a progression in the quality of the diffraction data, which improved from 3.3 to 3.0 to 2.8 Å. On the second occasion, the diffraction was improved by a crystal-annealing procedure. The crystals belong to the monoclinic space group P2₁, with unit-cell parameters a = 110.6, b = 294.2, c = 190.4 Å, β = 101.6°. The asymmetric unit contains three molecules of yeast F₁, with a corresponding volume per protein weight (V_M) of 2.8 ų Da⁻¹ and a solvent content of 55%.