Research Project
Full description The SNX5 and SNX6 members of the sorting nexin (SNX) protein family possess bin/amphiphysin/rvs (BAR) domains that form heterodimeric complexes with SNX1 and SNX2. These complexes regulate membrane trafficking of transmembrane receptors in endosomal compartments. The SNX5 and SNX6 proteins can be hijacked by Chlamydia trachomatis during cellular infection, via binding of the inclusion membrane protein IncE to the extended SNX5 and SNX6 phox homology (PX) domains. SNX32 is closely related to SNX5 and SNX6, however its structure and function is unknown. Here we have crystallised and determined the X-ray crystal structure of the human SNX32 PX domain in a stabilised complex with IncE at 2.3 A resolution. The structure of the SNX32 PX domain is highly similar to that of SNX5 determined previously, and it is able to bind to IncE in an analogous manner via a highly conserved binding groove at the base of its extended helix-turn-helix appendage. This further supports the evidence that the bacterial IncE protein is able to mimic and compete with endogenous cellular proteins that bind to the PX domains of SNX-BAR proteins.