Substrate transport across the outer membrane of Caulobacter crescentus

• Applicant: Professor Dr. Volkmar Braun
• Subject Area: Metabolism, Biochemistry and Genetics of Microorganisms
• Term: from 2004 to 2007
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 5468788

The genome sequence of Caulobacter crescentus (Cc) predicts an unusually high number of outer membrane proteins of which most (67) are proposed to transport nutrients energy-coupled via the Ton system into cells. The habitat of Cc (lakes and rivers) usually contains very low concentrations of nutrients of which insufficient amounts may pass through the outer membrane by diffusion. The project will examine the prediction of TonB coupled transport for a number of nutrients (sugars, oligosaccharides, amino sugars, amino acids, peptides, nucleosides) and characterize the role TonB plays in nutrient uptake. If the prediction of TonB coupled transport turns out to be wrong for most of the proteins, we will study a few uptake systems to find out why the Cc proteins have more than double the size of hitherto characterized porins.

• DFG Programme: Research Units
• Subproject of: FOR 449: Bacterial Cell Envelope: Synthesis, Function and Target