Methanogens are fastidious anaerobes whose metabolism centers around the reduction of CO2 to CH4. These unique organisms have been classified a """"""""archaebacteria"""""""" with characteristics evolutionarily distinct from procaryotes and eukaryotes. Many aspects of cellular metabolism in these organisms are unclear. In this proposal in vivo and in vitro NMR spectroscopy will be used to unravel carbon and nitrogen assimilation and specific aspects of bioenergetics in Methanobacterium thermoautotrophicum strain DeltaH. Specifically, we will (i) elucidate the exact role of 2,3-Cyclopyrophospho-glycerate (CPP), the major soluble carbon and phosphorus pool, in gluconeogenesis using 13C NMR; (ii) purify and characterize the enzymes that synthesize and degrade CPP; (iii) examine the unique CO2 fixation pathway that gives rise to asymmetric labeling of acetyl coenzyme A (using 13C NMR); (iv) further characterize nitrogen assimilation using 15N NMR; and (v) monitor cell bioenergetics with 31p NMR. The results of this work should lead to a better understanding of the metabolic role of CPP, (a novel intermediate in carbohydrate synthesis) and of how carbon and nitrogen assimilation are regulated in this methanogen, and to a comparison of metabolic pathways with other more common organisms.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM033463-04
Application #
3283213
Study Section
Physical Biochemistry Study Section (PB)
Project Start
1986-12-01
Project End
1990-11-30
Budget Start
1988-12-01
Budget End
1990-11-30
Support Year
4
Fiscal Year
1989
Total Cost
Indirect Cost
Name
Boston College
Department
Type
Schools of Arts and Sciences
DUNS #
045896339
City
Chestnut Hill
State
MA
Country
United States
Zip Code
02467
Lai, M C; Sowers, K R; Robertson, D E et al. (1991) Distribution of compatible solutes in the halophilic methanogenic archaebacteria. J Bacteriol 173:5352-8
Robertson, D E; Roberts, M F (1991) Organic osmolytes in methanogenic archaebacteria. Biofactors 3:1-9
Roberts, M F; Choi, B S; Robertson, D E et al. (1990) Free amino acid turnover in methanogens measured by 15N NMR spectroscopy. J Biol Chem 265:18207-12
Robertson, D E; Lesage, S; Roberts, M F (1989) Beta-aminoglutaric acid is a major soluble component of Methanococcus thermolithotrophicus. Biochim Biophys Acta 992:320-6
Belay, N; Sparling, R; Choi, B S et al. (1988) Physiological and 15N-NMR analysis of molecular nitrogen fixation by Methanococcus thermolithotrophicus, Methanobacterium bryantii and Methanospirillum hungatei. Biochim Biophys Acta 971:233-45
Choi, B S; Roberts, M F (1987) 15N-NMR studies of Methanobacterium thermoautotrophicum: comparison of assimilation of different nitrogen sources. Biochim Biophys Acta 928:259-65