ABL2/ARG (ABL-related gene) belongs to the ABL (Abelson tyrosine-protein kinase) 
family of tyrosine kinases. ARG plays important roles in cell morphogenesis, 
motility, growth and survival, and many of these biological roles overlap with 
the cellular functions of the ABL kinase. Chronic myeloid leukemia (CML) is 
associated with constitutive ABL kinase activation resulting from fusion between 
parts of the breakpoint cluster region (BCR) and ABL1 genes. Similarly, fusion 
of the ETV6 (Tel) and ARG genes drives some forms of T-cell acute lymphoblastic 
leukemia (T-ALL) and acute myeloid leukemia (AML). Dasatinib is a tyrosine 
kinase inhibitor used for the treatment of CML by inhibiting ABL, and while it 
also inhibits ARG, there is currently no structure of ARG in complex with 
dasatinib. Here, the co-crystal structure of the mouse ARG catalytic domain with 
dasatinib at 2.5 Å resolution is reported. Dasatinib-bound ARG is found in the 
DFG-in conformation although it is nonphosphorylated on the activation-loop 
tyrosine. In this structure the glycine-rich P-loop is found in a relatively 
open conformation compared with other known ABL family-inhibitor complex 
structures.