Preliminary X-ray diffraction studies of the external functional unit RtH2-e from the Rapana thomasiana

The `external' oxygenated functional unit RtH2-e of the Rapana hemocyanin subunit RHSS2 was isolated and crystallized. X-ray intensity data to 3.3 Å resolution have been collected at 100 K and the structure has been solved using the molecular-replacement method. The space group is assigned to be the tetragonal P4₃2₁2, with unit-cell parameters a = b = 105.5, c = 375.0 Å.