Xanthomonas campestris pv. glycines 8ra produces proteinaceous bacteriocin, glycinecinA against the related pathogen, however biochemical characterization of glycinecinA has not been reported. Biochemical aspects of glycinecinA are an essential goal to study its mode of action on sensitive cells, with a view at evaluating its possible utilization as a biological control agent. Recently, about 1.7 kb DNA fragment responsible for production of glycinecinA has been cloned, and sequenced. Possible open reading frames were expressed in Esherichia coli DH5 a, and expressed proteins were was purified with usual protocols of bacteriocin purification, consisting of ammonium sulfate precipitation and column chromatography. The molecular mass of glycinecinA was estimated to be approximately 54 kDa polypeptide, consisting of two subunits as analyzed by SDS-PAGE. The purified active glycinecinA was heterodimer of these two subunits deduced from cross-linking reaction and gel-filtration chromatography. The result of N-terminal protein sequencing indicated that these two subunits have signal peptides necessary to pass through the cytoplasmic membrane.