Preliminary crystallographic analysis of the oxidized form of a two mono-nuclear iron centres protein from Desulfovibrio desulfuricans ATCC 27774

Abstract

Crystals of the fully oxidized form of desulfoferrodoxin were obtained by vapor diffusion from a solution containing 20% PEG 4000, 0.1 M HEPES buffer, pH 7.5, and 0.2 M CaCl2. Trigonal and/or rectangular prisms could be obtained, depending on the temperature used for the crystal growth. Trigonal prisms belong to the rhombohedral space group R32, with a = 112.5 Å and c = 63.2 Å; rectangular prisms belong to the monoclinic space group C2, with a = 77.7 Å, b = 80.9 Å, c = 53.9 Å, and β =98.1°. The crystallographic asymmetric unit of the rhombohedral crystal form contains one molecule. There are two molecules in the asymmetric unit of the monoclinic form, in agreement with the self-rotation function.