Requirement of periplasmic chaperones in protein import

• Applicant: Professor Dr. Volkmar Braun
• Subject Area: Metabolism, Biochemistry and Genetics of Microorganisms
• Term: from 2008 to 2012
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 57648236

We discovered that the activity of an imported protein depends on a specific periplasmic chaperone. A protein toxin, colicin M, kills only cells that synthesize the FkpA chaperon. This finding assigns for the first time a function to FkpA, relates a periplasmic chaperone to a protein import rather than to folding and assembly of newly synthesized exported proteins, and allows selection of inactive FkpA mutant proteins. It is proposed to elucidate the activation mechanism of colicin M by FkpA using in vivo and in vitro experiments. In addition, colicin M will be used to specifically select fkpA mutants to study the functions of the N- and C-domains of FkpA.

• DFG Programme: Research Grants