the N- and C-terminal fragments, they likely have undergone cleavage during the crystallization process, as we found that the form of the protein that provided suitable crystals was shorter than the one present in freshly purified preparations used for AUC and DXMS (see Methods). A disulfide bond formed by Cys203 and Cys385 was found to be partially disrupted, most likely due to radiation damage from the X-ray beam.
