Sequence alignment of human ABL1b and ABL2b. Identity (*) and strong or weak sequence conservation [(:)colon for strong conservation; (.) period for weak conservation] are indicated. Domains are indicated with the following underlines: plain, SH3; heavy, SH2; dashed, TK; or wavy, terminal F-actin binding. Shading is used to highlight the following features: sequences deleted in human leukemogenic ABL fusions (gray), phosphorylation sites with known function (red), SH3 and WW domain proline-rich ligands (yellow), K- or R-rich NLS motifs (purple), and NES (blue). Additional reported phosphorylation sites are indicated with a red over-line. The DFG kinase signature is italicized. Alignment was performed using ClustalW (248).