YggB of Corynebacterium glutamicum [Elektronische Ressource] : dual function in osmotic stress response and glutamate production / vorgelegt von Kirsten Börngen

YggB of Corynebacterium glutamicum - Dual function in osmotic stress response and glutamate production Inaugural-Dissertation zur Erlangung des Doktorgrades der Mathematisch-Naturwissenschaftlichen Fakultät der Universität zu Köln vorgelegt von Kirsten Börngen aus Köln Köln, September 2009 Berichterstatter: Prof. Dr. Reinhard Krämer Prof. Dr. Arnd Baumann Tag der Disputation: 27.11.2009 „Phantasie ist wichtiger als Wissen, denn Wissen ist begrenzt“ Albert Einstein Abstract Abstract The membrane protein YggB of Corynebacterium glutamicum was previously described to belong to the MscS-type family of mechanosensitive (MS) channels functioning as emergency valves upon osmotic downshift. Bacterial cells respond to rapid water influx by immediate activation of MS channels that allow efflux of compatible solutes to prevent cell lysis. Recently, YggB was also connected to the glutamate export in C. glutamicum under glutamate productive conditions. The mechanism of glutamate export is not fully understood so far although C. glutamicum has been used for the industrial production of amino acids for decades. Deletion of yggB led to a drastic decrease in glutamate excretion while truncation of 110 AA resulted in continuous export of glutamate.