The final model proved highly accurate based on the following validation. The overall Z-score of the resulting hybrid model was -1.4 using internal quality evaluation of YASARA Structure. A Z-score indicates the number of standard deviations the model quality is away from the average high-resolution X-ray structure. Moreover, a Ramachandran plot  of the final model showed that 90.7% of all the residues were found in the most favored regions, 8.4% in additional allowed regions, and only 0.3% in disallowed regions (Additional file 5: Figure S3). These results indicated that the backbone dihedral angles were highly accurate. The ERRAT value, as an overall quality score, was 98.4% (Additional file 6: Figure S4). The final model of the CsMRP4 in PDB format can be found in Additional file 7.