Joseph Krzycki

Joseph Krzycki is a Professor of Microbiology at The Ohio State University, affiliated with the College of Arts and Sciences. He holds a B.S. from the University of Nebraska, Lincoln, and M.S. and Ph.D. from the University of Wisconsin, Madison. His research focuses on the biochemistry and molecular biology of methanogenic archaea, particularly the genetic and enzymatic mechanisms underlying methanogenesis and the role of pyrrolysine, the 22nd genetically encoded amino acid. His lab has discovered how methanogens use pyrrolysine to synthesize proteins critical for methylamine metabolism and has elucidated its biosynthesis pathway from lysine. Key contributions include the identification of pyrrolysine’s genetic encoding via UAG codons, its structural role in methyltransferases, and its presence in diverse bacteria and archaea, including human gut microbes.

Research highlights include studies on the RamA protein’s role in corrinoid activation, the structural basis of pyrrolysine function, and the evolutionary implications of genetic code expansion. His work has advanced understanding of microbial metabolism, enzyme mechanisms, and applications of synthetic biology. Krzycki collaborates on projects analyzing deep subsurface microbial ecosystems and gut microbiota’s role in cardiovascular disease. He is a member of the Ohio State Biomedical Partnership (OSBP) and the Center for RNA Biology.

Publications span over four decades, with seminal contributions to methanogen biochemistry, including foundational studies on methylamine methyltransferases and pyrrolysine’s discovery. His lab’s findings have practical implications for biotechnology, such as engineered proteins with novel chemical properties.