Structure of the tandem PX-PH domains of Bem3 from Saccharomyces cerevisiae

The structure of the putative membrane-binding tandem PX-PH domain module of the yeast protein Bem3 is reported.
The structure of the tandem lipid-binding PX and pleckstrin-homology (PH) domains of the Cdc42 GTPase-activating protein Bem3 from Saccharomyces cerevisiae (strain S288c) has been determined to a resolution of 2.2 Å (R work = 21.1%, R free = 23.4%). It shows that the domains adopt a relative orientation that enables them to simultaneously bind to a membrane and suggests possible cooperativity in membrane binding.