PRODUCTION OF A RENIBACTERIUM-SALMONINARUM HEMOLYSIN FUSION PROTEIN IN ESCHERICHIA-COLI K12

Gene rsh encoding a novel hemolysin of Renibacterium salmoninarum was fused to the lacZ gene of the pAX5+ plasmid vector to facilitate produ ction of a 160 kDa beta-galactosidase fusion protein. The soluble fusi on protein was produced cytoplasmically in Escherichia coli XL1-Blue a nd purified using affinity chromatography. The fusion protein retained epitopes which were identified in components present in in vitro cult ures of R. salmoninarum. Western blots of R. salmoninarum cell extract s which were probed with an antiserum raised against the affinity puri fied fusion protein predominantly recognized bands of apparent molecul ar weights 82 and 78 kDa as well as a number of other bands which may represent breakdown products of the native protein. No components were detected in extracellular products and iron-restricted culture condit ions did not obviously affect the production of these components.