eLife assessment
BTK, a TEC-family tyrosine kinase activated by the B-cell antigen receptor, contains a variety of regulatory domains and it is subject to complex regulation by membrane phospholipids, protein ligands, phosphorylation, and dimerization. This study presents convincing evidence, utilizing various biophysical techniques, to support a model for BTK activation that will be valuable for the field. Overall, the study enhances the understanding of BTK's activation mechanism, autoinhibition, and allosteric control, challenging previous assumptions about BTK.