Professor

Molecular Biology and Genetics

Cornell University (Ithaca, NY)

Protein engineering of plant cell wall degrading enzymes.

My laboratory studies the enzymology of plant cell wall degradation with a major focus on cellulases. Enzymes that degrade insoluble substrates have important differences from most enzymes whose substrates are small soluble molecules. In addition, cellulases are important industrial enzymes and have potential in the production of renewable, non-polluting fuels and chemicals. I am using a combination of genomics, protein engineering, and molecular biology in my research. I have been studying the high G-C gram variable soil bacterium, Thermobifida fusca, a moderate thermophile, for more than 20 years, as it is a major microorganism degrading plant cell walls in heated plant wastes such as compost piles. Its genome sequence has been finished by the Joint Genome Institute of the DOE (http://genome.jgi-psf.org/draft_microbes/thefu/thefu.home.html). I have cloned, expressed and characterized the activity of the expressed proteins of six cellulase genes, two xylanase genes, a xyloglucanase gene, a b-1,3 glucanase gene, a b-glucosidase gene,two cellulose binding protein genes and a regulatory gene, CelR. Three-dimensional structures have been determined for the catalytic domains of three of the cellulases and the xyloglucanase, while structures for a cellulase and the b-1,3 glucanase are being determined. Extensive site directed mutagenesis studies have been carried out on three of the cellulases.

1966-1967 Post-doctoral fellow at John Hopkins Medical School

2003 Fellow American Academy of Microbiology