Coatomer is a multisubunit complex involved in trafficking of vesicles between the endoplasmatic reticulum and the Golgi apparatus. From sequence homologies, all seven subunits, α-, β-, β'-, γ-, δ-, -, and ζ-COP, are encoded in the genome of Trypanosoma brucei. The complete predicted amino-acid sequences of β-, β'-, and ζ-COP show only 20-30% identity with higher eucaryotic homologues. The trypanosome coatomer complex was partially purified using a procedure similar to that used for bovine coatomer.