X-ray diffraction data for the four-CHRD region of human Chordin bound to a heparin-sulphate oligomer

The 4-CHRD region of human chordin was crystallised via the in-situ proteolysis technique, in the prescence of heparin oligosaccharide DP4 (average number of units 4). Data was collected at the Diamond Light source on 2024-09-22 and the structure was solved using the merging of two crystals. The solvent content of the crystal is high, with significant flexibility between subdomains, resulting in very diffuse density, and very high scaling and atomic B factors which seem to result from the conformational heterogeity. The structural information had to be interpretted conservatively, and although it was possible to locate the binding positions of several sulphate groups and the overall direction of the heparin molecule, there is significant ambiguity which we describe in the publication. It appears likely that improvements in processing software, or specific expert level workflows may yield improvements to the analysis of this data, and since this is a challenging example of a multi-domain human glycoproteins with unusual levels of movement within the lattice (given the apparent data resolution which is just below 3Å), it might be a useful resource for development of tools to study heterogeneity/flexibility within macromolecular crystal systems.