Crystallization and preliminary X-ray studies of plastocyanin from Silene expressed in E. coli

Plastocyanin from Silene (SilPc) expressed in E. coli has been crystallized in a form suitable for X-ray diffraction analysis by a macroseeding method using ammonium sulfate as a precipitant in acetate buffer (pH = 5.5). These crystals belong to the trigonal space group P3₁21 or P3₂21 with lattice parameters a = b = 76.6, c = 65.5 Å, indicating an asymmetric unit containing two plastocyanin molecules. The crystals diffracted to at least 2.0 Å.