Mechanism of formation of the carboxyl of acetate by acetogenic bacteria

Technical Report · Sun Jan 01 04:00:00 EST 1989

DOI:https://doi.org/10.2172/5391012· OSTI ID:5391012

The overall goal of this project is to understand how the carboxyl of acetate is formed by acetogenic bacteria. Our work involves a multidisciplinary approach towards understanding the details of this process which is a key step in the pathway by which anaerobic bacteria synthesize acetyl-CoA. We have used a number of techniques including spectroscopy, enzyme kinetics, electrochemistry, and molecular biology. Figure 1 summarizes our current concept for how this pathway occurs. Our work focuses on carbon monoxide dehydrogenase (CODH). During this year, the sequences of the genes encoding the two subunits of CODH have been determined in a collaboration between labs. Thus, we now know the complete amino acid sequence of CODH. We made major progress in studies of the structure and function of metal centers in the nickel, iron-sulfur protein, CODH. CODH was found to contain one (4Fe-4S) cluster, a (Ni-Fe-C) center, and a (2Fe) center with two oxidation reduction potentials. We postulate that the site for binding CO is a mixed metal center that contains a (4Fe-4S) center bonded to a nickel site by a ligand bridge. One of the metal centers on CODH is the methyl binding site. We discovered that methylation of CODH by the methylated-C/Fe-SP involves reductive activation of a metal center followed by formation of the methyl-metal intermediate. 15 refs., 6 figs.

• Research Organization: Wisconsin Univ., Madison, WI (USA)
• Sponsoring Organization: DOE/ER
• DOE Contract Number: FG02-88ER13875
• OSTI ID: 5391012
• Report Number(s): DOE/ER/13875-T1; ON: DE90003587
• Country of Publication: United States
• Language: English

Related Subjects

09 BIOMASS FUELS
090900* -- Biomass Fuels-- Processing-- (1990-)
550200 -- Biochemistry
59 BASIC BIOLOGICAL SCIENCES
ACETATES
ALCOHOLS
ANAEROBIC CONDITIONS
BIOCHEMICAL REACTION KINETICS
BIODEGRADATION
BIOLOGICAL PATHWAYS
BIOSYNTHESIS
CARBOXYLIC ACID SALTS
CHEMICAL REACTIONS
DECOMPOSITION
DOCUMENT TYPES
ENZYMES
HYDROXY COMPOUNDS
KINETICS
METABOLISM
METHANOL
ORGANIC COMPOUNDS
OXIDOREDUCTASES
PROGRESS REPORT
REACTION KINETICS
SYNTHESIS