Graduate Students Mini Symposium III - 2026

13:15 h Zeynep Dogru - AG Kurth

Investigating the gene regulation and physiology of methoxydotrophic archaea

Lignin-derived methoxylated aromatic compounds (MACs) are abundant carbon sources, yet archaeal MAC degradation has only recently been recognized. Methermicoccus shengliensis performs methoxydotrophy via an O-demethylase system encoded by the widely distributed mto operon, underscoring the prevalence of Mto systems across diverse archaeal taxa. Although most Mto proteins have been characterized, two putative DNA-binding proteins remain uncharacterized; their role in mto gene regulation investigated using promoter pull-down assays and mass spectrometry. To further clarify the metabolic significance of Mto systems in archaea, Methanolacinia petrolearia, a hydrogenotrophic methanogen encoding Mto proteins but lacking known MAC transporters, is examined to determine substrate specificity and potential methyl halide detoxification through growth experiments, enzyme activity assays, and RT-qPCR analysis.

13:45 h Sindi Tejera Santos - AG Bischofs-Pfeifer
tba

14:15 h Johannes Willemsen - AG Kurth

Biochemical and functional characterizations of the O-demethylase system from the methanogenic archaeon Methermicoccus shengliensis

The methanogen Methermicoccus shengliensis can produce methane from methoxylated aromatic compounds (MACs) due to its O-demethylase system. We aim to better understand the underlying protein-protein interactions of this four-component system, and to unravel why two paralogs of the MAC-demethylating enzyme (MTI) are encoded within the genome. Although the corrinoid and MTI proteins can assemble into heteromeric complexes, such assembled state does not appear to be essential for either activation or demethylation of the corrinoid protein. Furthermore, MTI activity assay data and RT-qPCR data imply that one of the MTI enzymes prefers multi-methoxylated MACs, while the other may prefer mono-methoxylated MACs.