Figure 1.

Mechanism of KIT activation by SCF. The receptor tyrosine kinases class III (RTK-IIIs) kit receptor is characterized by an ectodomain (pdb 2ec8) composed of five Ig-like domains a single membrane-spanning helix, and a conserved tyrosine kinase domain (TKD). Membrane distal domains 1–3 form a shallow groove accessible to SCF solution dimer. Binding of dimeric SCF promotes kit dimerization, facilitating conformational reorganization where weak homo cis interactions mediated by domains 4 and 5 contribute to establishing and/or maintaining induced kinase activity (pdb 2ew9).