Isolating membrane proteins has long remained a bottleneck in the quest for structural and functional characterisation for many classes of membrane proteins. Nevertheless, the yeast host system, Pichia pastoris, has been highly successful in the production of eukaryotic membrane proteins, due to its possession of many ‘higher’ eukaryote traits including post-translational modifications and protein processing pathways. Within mitochondria, more than 40% of proteins are associated with or integrated into a membrane and yet there are only a handful of crystal structures available of mitochondrial membrane proteins including only one integral outer membrane protein, namely VDAC.  I am characterising the mitochondrial Sorting and Assembly Machinery (SAM) which is a membrane embedded multi-protein complex essential for the targeting and assembly of proteins, that adopt a ß-barrel topology, into the outer membrane of mitochondria. To do so, I have extended previously established techniques in Pichia pastoris to produce large quantities of the SAM subunits in their native form for structural studies. By applying this novel approach, I aim to elucidate the molecular architecture of the SAM complex and shed new light on the fundamental process of mitochondrial protein import and assembly.