3NRM:
reference: Discovery of imidazo[1,2-a]pyrazine-based Aurora kinase inhibitors., Belanger DB, Curran PJ, Hruza A, Voigt J, Meng Z, Mandal AK, Siddiqui MA, Basso AD, Gray K, Bioorg Med Chem Lett. 2010 Sep 1;20(17):5170-5174. Epub 2010 Jul 8. PMID: 20674350

This OCA Structure page
uses Jmol, developed by the Jmol Development Team (documentation).