PMID: 22248356

Authors:

Martin MP, Zhu JY, Lawrence H, Pireddu R, Luo Y, Alam R, Ozcan S, Sebti SM, Lawrence NJ, Schonbrunn E

Title:

A novel mechanism by which small molecule inhibitors induce the DFG flip in Aurora A.

Journal:

ACS Chem Biol. 2012 Jan 16.

Abstract:

Most protein kinases share a DFG (Asp-Phe-Gly) motif in the ATP site which can assume two distinct conformations, the active DFG-in and the inactive DFG-out states. Small molecule inhibitors able to induce the DFG-out state have received considerable attention in kinase drug discovery. Using a typical DFG-in inhibitor scaffold of Aurora A, a kinase involved in the regulation of cell division, we found that halogen and nitrile substituents directed at the N-terminally flanking residue Ala273 induced global conformational changes in the enzyme, leading to DFG-out inhibitors that are among the most potent Aurora A inhibitors reported to date. The data suggest an unprecedented mechanism of action, in which induced-dipole forces along the Ala273 side chain alter the charge distribution of the DFG backbone, allowing the DFG to unwind. As the ADFG sequence and three-dimensional structure is highly conserved, DFG-out inhibitors of other kinases may be designed by specifically targeting the flanking alanine residue with electric dipoles.