D.J. Ferguson
Assistant Professor of Microbiology
Research Interests: physiology of methyltrophic methanogenic archaea
Methanosarcina acetivorans is a methylotrophic methanogenic archaeon capable of growth in many environments and on a wide variety of substrates. Research on this and related organisms has revealed the existence of analogous pathways of methanol- and methylamine-dependent methanogenesis involving homologous corrinoid binding proteins and non-homologous methanol and methylamine methyltransferases. In close proximity to the genes encoding the methylamine specific methyltransferases and corrinoid proteins there have been genes encoding putative permeases: mtmP, mtbP, and mttP. The precise role of these putative permease genes has never been demonstrated. One of the goals of my laboratory is to demonstrate the role of these genes in methylamine dependent methanogenesis by generating knock-out mutants in M. acetivorans and by functional expression of the genes in E. coli.
The genes encoding the methylamine methyltransferases MttB, MtbB, and MtmB all contain an in-frame amber UAG codon. This UAG codon encodes the 22nd genetically encoded amino acid pyrrolysine. The genes necessary for the translation of the UAG codon are found within the pylTSBCD operon in Methanosarcina barkeri as well as other methylotrophic methanogens. Thus far, only limited evidence of horizontal gene transfer of the pyl operon exists, with the primary example being a Gram positive bacterium Desulfitobacterium hafniense, however the possibility remains that other organisms have obtained this gene cluster as well. Another goal of my laboratory will be to screen difficult to culture environmental isolates obtained in collaboration with Dr. Annette Bollmann which may be carrying the pyl operon.
Faculty: Ferguson