Research

The research in the Adams Laboratory focuses on the physiology of hyperthermophilic organisms with an emphasis on metal-containing enzymes in the hyperthermophilic marine archaeon Pyrococcus furiosus.
Project Description
Applied Enzymology Enzymes of biotechnological interest are being characterized from P. furiosus. The enzymes are mainly involved in amino acid metabolism and include amino acylases, prolidases, aminopeptidases and carboxypeptidases. The native and recombinant forms of the enzymes are obtained for comparative analyses.
Bioenergy The U. S. Department of Energy's BioEnergy Science Center (BESC) research program seeks to eliminate the dominant obstacle to cost-effective production of biofuels, namely, the conversion of cellulosic biomass to sugars. BESC- related research in the Adams laboratory will focus on evaluating the use of extremely thermophilic anaerobic microorganisms and enzymes derived from them to enhance the degradation of plant cell walls. Read more about the program from the DOE or visit the BESC.
Biological Electron Transfer A major limitation in engineering microorganisms to produce useful products such as biofuels is the lack of a fundamental understanding of how electron flow is controlled in metabolic pathways and in key redox enzymes. As part of the DOE’s Energy Frontier Research Center (EFRC) on Biological Electron Transfer and Catalysis (BETCy), a multi-institutional program led by Montana State University, we are studying the mechanism and structural basis of electron transfer in electron bifurcating enzymes including hydrogenases and transhydrogenases. These serve as key points of divergence and convergence of electron flow in primary metabolic pathways.
Hydrogenase Biosythesis P. furiosus contains three hydrogenases, two located in the cytoplasm and one membrane-bound. The goal of this project is to obtain recombinant forms of all three enzymes. This also includes characterizing the enzymes involved in the biosynthesis and maturation of these hydrogenases.
Iron Metabolism In this project we are investigating the ability of P. furiosus to respond to iron limitation and to metabolize insoluble forms of iron. The primary tools are physiological studies coupled to DNA microarray analyses.

Metalloproteins and Metallomes

We are developing techniques to discover new metalloproteins and to better understand an organism’s “metallome”. We are capable of studying the uptake, limitation, utilization and toxicity of up to 53 metals in order to help unlock their physiological and cellular roles. Our metal analyses range from simple colorimetric assays to our extremely sensitive inductively coupled plasma mass spectrometer (ICP-MS). This is part of the ENIGMA project funded by the Genomics: GTL program of the DOE.
Primary Carbon Metabolism Of the 2,200 genes in the genome of P. furiosus, about half are of completely unknown function. They are referred to as the 'conserved hypothetical', as they show sequence similarity only to unknown genes in other organisms. We are using microarray-based analyses in combination with biochemical studies to assess the function of these unknown genes in the primary pathways of carbon metabolism.
Stress Response This project focuses on how P. furiosus responds to a variety of stresses, in particular, exposure to oxidative and reactive nitrogen compounds, and to cold-shock. The responses are being investigated at the level of gene expression using DNA microarrays. The relevant proteins are being characterized using conventional biochemical approaches.
Sulfur and Hydrogen Metabolism P. furiosus is able to grow well using sugars as a carbon source in the absence of sulfur by disposing of excess reductant in the form of hydrogen gas. If sulfur is added, it is reduced to hydrogen sulfide and less hydrogen is produced. However, significant growth on peptides takes place only in the presence of sulfur. The role of sulfur and hydrogen in the metabolism of this organism is being investigated using biochemical assays and protein purification, using information obtained from DNA microarray analyses.
Tungsten Metabolism Tungsten is a metal that is seldom used in biological system. Most life forms use the analgous element molybdenum, but the growth of P. furiosus is dependent upon tungsten. We have purified four tungstoenzymes from P. furiosus and there appear to be three ORFs in the genome that contain related enzymes. The overall objectives are to characterize the enzymes and to determine their physiological roles.