John Leigh
Professor of Microbiology

Website
COS Profile
Email: leighj@u.washington.edu
Phone:(206) 685-1390, (206) 543-0177, (206) 543-7045
Office Location: Health Sciences E-311
Campus Box: 357242

Research:

Dr. Leigh received his Ph.D. at the University of Illinois, and did his postdoctoral work at Massachusetts Institute of Technology in the Department of Biology.

Leigh’s lab combines an evolutionary perspective with a focused molecular approach. We work with Methanococcus maripaludis, a member of the methanogenic Archaea. The methanogens evidently originated early in the evolution of life. Today they occupy anaerobic habitats ranging from hydrothermal vents to animal digestive tracts, where most species grow on hydrogen and carbon dioxide and produce methane as a catabolic product. With effective genetic tools and a completed genome sequence, M. maripaludis has become a good laboratory model. Much of the lab concentrates on nitrogen regulation as a model for regulation in the Archaea. We discovered two novel mechanisms for the regulation of nitrogen fixation, one involving transcriptional repression and the other involving direct binding of regulatory proteins to nitrogenase.

Recent technologies for studying global regulation have produced a renaissance in microbial physiology. We have implemented the continuous culture of M. maripaludis in anaerobic chemostats, and we are using expression arrays to analyze the response to hydrogen-limitation. Proteomic analysis, in collaboration with M. Hackett, complements the array analysis. In addition, Leigh is a participating faculty member in the Astrobiology Program at the University of Washington.

Selected Publications:

Lie, T. J., G. E. Wood, and J. A. Leigh. 2005. Regulation of nif expression in Methanococcus maripaludis: Roles of the euryarchaeal repressor NrpR, 2-oxoglutarate, and two operators. J. Biol. Chem. 280:5236-5241.


Dodsworth, J. A. and J. A. Leigh. 2006. Regulation of nitrogenase by 2-oxoglutarate-reversible, direct binding of a PII-like nitrogen sensor protein to dinitrogenase. Proc. Natl. Acad. Sci. USA 103:9779-9784.


Hendrickson, E. L., A. K. Haydock, B. C. Moore, W. B. Whitman, and J. A. Leigh. 2007. Functionally distinct genes regulated by hydrogen limitation and growth rate in methanogenic Archaea. Proc. Natl. Acad. Sci. USA 104:8930-8934.


Hendrickson, E. L., and J. A. Leigh. 2008. Roles of coenzyme F420-reducing hydrogenases and hydrogen- and F420-dependent methylenetetrahydromethanopterin dehydrogenases in reduction of F420 and production of hydrogen during methanogenesis. J. Bacteriol. 190:4818-4821