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

ACS Chem Biol. 2012 Apr 20;7(4):698-706. doi: 10.1021/cb200508b. Epub 2012 Jan 27.


Most protein kinases share a DFG (Asp-Phe-Gly) motif in the ATP site that 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.

MeSH terms

  • Aurora Kinases
  • Cell Division
  • Drug Design
  • Humans
  • Oligopeptides / chemistry
  • Oligopeptides / pharmacology*
  • Protein Conformation / drug effects
  • Protein Kinase Inhibitors / pharmacology*
  • Protein Serine-Threonine Kinases / chemistry*
  • Protein Serine-Threonine Kinases / drug effects*


  • DFG peptide
  • Oligopeptides
  • Protein Kinase Inhibitors
  • Aurora Kinases
  • Protein Serine-Threonine Kinases

Associated data

  • PDB/3UNJ
  • PDB/3UNK
  • PDB/3UNZ
  • PDB/3UO4
  • PDB/3UO5
  • PDB/3UO6
  • PDB/3UOD
  • PDB/3UOH
  • PDB/3UOJ
  • PDB/3UOK
  • PDB/3UOL
  • PDB/3UP2