Oxysterol-binding protein that may be involved in the transport of sterols between the ER and the Golgi. Binds beta-sitosterol. Required for ovule fertilization. Interacts with PVA12. Interaction with PVA12 is necessary for targeting to the ER. Located in the Golgi in the absence of interaction with PVA12. Expressed in roots, leaves, stems, flowers and pollen. Unfertilized ovules, but normal pollen tube attraction. Belongs to the OSBP family.