Activating mutations leading to drug susceptibility

Crystallography of known inhibitors to EGFR and mutant EGFR are consistent with these observations. Both erlotinib,69 and gefitinib,68 have been crystallized to EGFR, and show the active form of the kinase (Table 5.1). Both 

The activating effect of the various deletion mutants prior to the C-helix is also interpretable by a review of the crystal structures of the inactive form of the kinase. In this C-helix-out form, the helix itself is unwound a turn compared to the active form, and the amino acid chain connecting the P-loop to the helix is extended.70 Removing a portion of this sequence would result in 

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