My research interests are the structure and function of enzymes and proteins important in infectious diseases, such as bacterial pathogenesis factors or antibiotic targets, as well as human related proteins associated with diseases like cancer. I am currently working on serine hydrolases in Staphylococcus aureus as new probe and drug targets. I also elucidate the role of histone proteins in nucleosomes in connection with cancer and developmental defects. I am also part of multiple collaborative projects. These include lanthanide-dependent bacterial metabolisms, zinc membrane transport, ethylene forming enzymes and bacterial racemases. These projects tackle aspects of various diseases, fundamental biology, the global waste problem and climate change.

I have expertise in molecular biology, protein expression and purification, biochemical assay and all aspects of X-ray crystallography. My daily toolkit includes enzyme assay development, directed mutagenesis of active site residues, screening substrate-specificity, and measuring kinetic profiles, as well as structure determination with of over 50currently deposited entries in the protein databank.

• Fellner, M., Lentz, C. S., Jamieson, S. A.,Brewster, J. L., Chen, L., Bogyo, M., Mace, P. D. (2020), Structural Basis for the Inhibitor and Substrate Specificity of the Unique Fph Serine Hydrolases of Staphylococcus aureus. ACS Infectious Diseases, 6, 2771-2782. (Chosen as the cover article)

• Fellner, M., Hausinger, R. P., Hu, J. (2018),A structural perspective on the PP-loopATP pyrophosphatase family. Critical Reviews in Biochemistry and Molecular Biology, 53, 607-622.

• Fellner, M., Rankin, J. A.*, Desguin, B., Hu, J., Hausinger, R. P. (2018), Analysis of the Active Site Cysteine Residue of the Sacrificial SulfurInsertase LarE from Lactobacillus plantarum. Biochemistry, 57, 5513-5523

• Fellner, M.*, Desguin B.*, Hausinger R. P., Hu J. (2017), Structural insights into the catalytic mechanism of a sacrificial sulfur insertase of the N-type ATP pyrophosphatase family, LarE. Proceedings of the National Academy of Sciences, 114, 9074-9079.