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Title: Enzymological studies of one-carbon reactions in the pathway of acetate utilization by methanogenic bacteria: Annual technical report for the period February 1, 1988--January 31, 1989

Technical Report ·
OSTI ID:6463189

Our current understanding of the pathway of acetate conversion to methane in Methanosarcina thermophila is depicted. Our accomplishments this past year include phosphotransacetylase, the corrinoid/Fe-S protein component of the carbon monoxide dehydrogenase, and ferredoxin were characterized in further detail; two methyl transferase activities were resolved; and putative positive clones containing the phosphotransacetylase gene were isolated from a lambda gt 11 DNA library of M. thermophila. The phosphotransacetylase was purified to electrophoretic homogeneity and characterized. The specific activity was 2555 micromoles of acetyl-CoA/min/mg. Optimum activity is obtained between 35-45 /degree/C and pH 6.5-7.5 in the presence of potassium or ammonium ions(ca. 100 mM). The enzyme is purified as a monomer of Mr 43,000. The Km and Vmax for CoASH and acetyl phosphate are 91 and 165 micromolar, and 5517 and 4025 micromoles/min/mg. Anti-phosphotransacetylase antibodies were raised in rabbits which were used in an immunoblot of crude extracts from acetate- or methanol-grown cells; the results indicate regulation of synthesis in response to the growth substrate. A mixed oligonucleotide probe was synthesized using the DNA sequence deduced from the N-terminal amino acid sequence. 6 figs.

Research Organization:
Virginia Polytechnic Inst. and State Univ., Blacksburg (USA)
DOE Contract Number:
FG05-87ER13730
OSTI ID:
6463189
Report Number(s):
DOE/ER/13730-2; ON: DE89006907
Resource Relation:
Other Information: Paper copy only, copy does not permit microfiche production
Country of Publication:
United States
Language:
English