Expression of the Kirsten ras viral and human proteins in Escherichia coli

E T Nakano, M M Rao, M Perucho, M Inouye
1987 Journal of Virology  
The expression vectors pINIII-A and pINIII (Ipp p5) were used to construct plasmids which direct the synthesis in Escherichia coli of the Kirsten ras viral (v-Ki-ras) and human cellular (c-Ki-ras) oncogene products as fusion proteins containing 9 and 10 extra amino acids, respectively, at their N termini. Authenticity of the bacterially produced proteins was determined by immunoprecipitation and immunoblot analyses with ras-specific monoclonal antibodies. After induction with
more » ... galactopyranoside, the viral protein represented approximately 20% of the total cellular protein. The majority of the protein was found in the postsonication low-speed centrifugation pellet. The synthesized viral protein was active in GTP binding, as judged by autophosphorylation and photoaffinity labeling assays. 302 on May 4, 2020 by guest Downloaded from EXPRESSION OF KIRSTEN ras PROTEINS 303 transform JA221 cells. The A2 reading frame of the expres-
doi:10.1128/jvi.61.2.302-307.1987 fatcat:kazqzbews5baxaznylf5cgak4q