CRYSTALLIZATION AND PRELIMINARY-X-RAY CRYSTALLOGRAPHIC STUDIES OF RUSTICYANIN FROM THIOBACILLUS-FERROOXIDANS

Rusticyanin is a 16.5 kDa type I blue copper protein isolated from Thiobacillus ferrooxidans. This organism can grow on Fe2+ as its sole energy source. Rusticyanin is thought to be a principal component in the iron respiratory electron transport chain of T. ferrooxidans. As a component of the periplasmic space of an acidophilic bacterium, rusticyanin is remarkably stable at acidic pH. It is redox-active down to pH 0.2. Crystals of rusticyanin have been grown from solutions of PEG 8000 by the hanging-drop vapor diffusion method. The crystals are orthorhombic, space group P212121, with unit cell dimensions a = 32.36 Å, b = 60.37 Å, c = 74.60 Å. The crystals diffract to 2.0 Å resolution and they are stable in the X-ray beam for at least two days. © 1992.