Figure 6.1.

Structural features of Pak kinases. Image represents the domain structure of Pak1. Pak1-3 contain an N-terminal regulatory domain and a C-terminal serine-threonine kinase domain. Several domains within the regulatory domain are indicated: The dashed areas represent the canonical proline-rich, SH3-binding domains. The adaptor proteins Nck and Grb2 bind to the first and second proline-rich domain, respectively. In black, the non-canonical, proline-rich PIX-binding domain is indicated. In dark-grey, the p21-binding domain (PBD) is indicated, which binds GTP-bound forms of Rac and cdc42. Partially overlapping with the PBD is the autoinhibitory domain (AID) in light-grey, which inhibits Pak activity in trans by binding to the catalytic domain of another Pak molecule.