Kahlson, M. A.; Ritho, J.; Gomez, J. V.; Wang, H.; Butterwick, J.; Dixon, S. J.

Small molecules serve as valuable tools for probing non-apoptotic cell death mechanisms. The small molecule CIL56 induces a unique form of non-apoptotic cancer cell death that is promoted by a complex formed between zinc finger DHHC-type palmitoyltransferase 5 (ZDHHC5) and an accessory protein, GOLGA7. However, the structure, function, and regulatory role of this complex in cell death remain poorly understood. In this study, we employ biochemical purification, cryogenic electron microscopy (cryo-EM), homology modeling, mutagenesis, and functional assays to elucidate the structure of the Zdhhc5-GOLGA7 complex. We identify key conserved residues in both Zdhhc5 and GOLGA7 that are necessary for complex formation and to promote non-apoptotic cancer cell death in response to CIL56. These results provide new insights into the structure and function of a death-promoting protein complex.