F-V FRAGMENT MEDIATED CRYSTALLIZATION OF THE MEMBRANE-PROTEIN BACTERIAL CYTOCHROME-C-OXIDASE

Crystallization of membrane proteins, a prerequisite for their X-ray c rystallographic analysis, remains difficult. Here, we demonstrate that the crystallization of the cytochrome c oxidase from Paracoccus denit rificans can be mediated by co-crystallization with an antibody F-v fr agment. The crystals obtained contain all-four subunits of this membra ne protein complex and the F-v fragment. The approach of co-crystalliz ing membrane proteins with antibody fragments should be useful in obta ining well-ordered crystals of membrane proteins in general.