Mitotic kinesin binding site

A ligand binding site of a KSP protein comprising the relative structural coordinates set forth in Table 5 ±the root mean square deviation from the backbone atoms of said amino acids is not more than about 2 Å.

A method for identifying an agent that interacts with a ligand binding site of human KSP, comprising the steps of:

• (a) determining a ligand binding site of KSP from a three-dimensional model of the KSP binding site as set forth in Table 5, ±the root mean square deviation from the backbone atoms of said amino acids of not more than about 2.0 Å;
• and
• (b) performing computer fitting analysis to identify an agent which interacts with said ligand binding site.

A machine-readable data storage medium, comprising a data storage material encoded with machine readable data which, when using a machine programmed with instructions for using said data, is capable of displaying a graphical three-dimensional representation of a molecular complex of a compound bound to the ligand binding site of human KSP, said three-dimensional representation comprising the structural coordinates of the KSP as set forth in a table selected from Tables 1-4 or a homologue of said molecular complex, wherein said homologue comprises a binding site that has a root mean square deviation from the backbone atoms of said KSP of not more than about 2.0 Å.

A method for determining the three-dimensional structure of a complex of KSP with a ligand thereof, which comprises obtaining X-ray diffraction data for crystals of the complex comprising the ligand bound to KSP at a ligand binding site;

• and utilizing said data to define the three-dimensional structure of the complex.