PufX organises RC-LH1, the photosynthesis reaction centre-light harvesting complex 1 core complex of Rhodobacter sphaeroides [1]. It also facilitates the exchange of quinol for quinone between the reaction centre and cytochrome bc(1) complexes. In organic solvent, PufX contains two hydrophobic helices which are flanked by unstructured regions and connected by a helical bend [1].

1: The solution structure of the PufX polypeptide from Rhodobacter sphaeroides. Tunnicliffe RB, Ratcliffe EC, Hunter CN, Williamson MP; FEBS Lett. 2006;580:6967-6971. PMID:17161397