Expression and rapid one-step purification of biologically active His-tagged factor C by Ni2+ affinity column chromatography

Factor C is an unusual extracellular protein capable of inducing cytodiffer entiation in certain Streptomyces strains. The protein is produced by Strep tomyces griseus 45H at such a low amount that the study of its mode of acti on was hindered by the shortage of purified protein. We report here the exp ression of C-terminally hexa-His-tagged factor C in Streptomyces lividans a nd Escherichia coli. Expression in S. lividans is low while in E. coli it i s relatively high, yielding about 5-10 mg of biologically fully active prot ein per liter culture. (C) 2001 Federation of European Microbiological Soci eties. Published by Elsevier Science B.V. All rights reserved.