Reference sequence and structure retrieval
For structural validation purpose, the modeled protein complex (hs CENP-HIKM) was compared with structural orthologs with known 3-dimensional structures. The reference sequences and structures were retrieved from the NCBI (National Center for Biotechnology Information) database [30], and the PDB (Protein Data Bank) [31]. 5Z08 and 6YPC which represent the PDB codes for the crystal structures of the fungal (Thielavia terrestris ) kinetochore CENP-HIK triple complex subunits and the yeast (Saccharomyces cerevisiae ) kinetochore CENP-HIKTW subunits respectively, were used for the retrieval of the corresponding structures from the protein data bank. The crystal structure of the human CENP-M was also retrieved with the PDB code 4P0T. The PDB codes for each structure were submitted to the NCBI database to obtain their corresponding amino acid sequences while the full length sequence for each subunit of the human CENP-HIK were retrieved using their respective accession numbers; Q9H3R5, Q92674 and Q9BS16.