Mechanism of formation of the carboxyl of acetate by acetogenic bacteria

Technical Report · Mon Jan 01 04:00:00 EST 1990

DOI:https://doi.org/10.2172/6941322· OSTI ID:6941322

Ragsdale, S W

The overall goal of this project is to understood how the carboxyl of acetate is formed by acetogenci bacteria. Our work involves a multidisciplinary approach toward 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. Our work focuses on carbon monoxide dehydrogenase (CODH). During this year, the sequences of the genes encoding the two subunits to CODH have been determined. Thus, we now know the complete amino acid sequence of CODH. We made major progress in studies of the structure and function of metals centers in the nickel, iron-sulfur protein, CODH, by Moessbauer electron nuclear double resonance (ENDOR) and EPR spectroscopic techniques and coulometric studies. CODH was found to contain one (4Fe--4S) cluster, a (Ni--Fe--C) center, and a (2Fe) center with two oxidation reduction potentials. In a description of the Moessbauer work we postulate that the site for binding CO is 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 for the methyl-metal intermediate. 15 refs., 6 figs.

• Research Organization: Wisconsin Univ., Milwaukee, WI (USA)
• Sponsoring Organization: DOE/ER
• DOE Contract Number: FG02-88ER13875
• OSTI ID: 6941322
• Report Number(s): DOE/ER/13875-2; ON: DE90011416
• Country of Publication: United States
• Language: English

Related Subjects

550200* -- Biochemistry
550700 -- Microbiology
59 BASIC BIOLOGICAL SCIENCES
ACETATES
ANAEROBIC CONDITIONS
BACTERIA
BIOLOGICAL PATHWAYS
CARBONYLS
CARBOXYLIC ACID SALTS
CLONING
COENZYMES
DNA HYBRIDIZATION
DNA SEQUENCING
DNA-CLONING
DOCUMENT TYPES
ENZYMES
GENETIC MAPPING
HYBRIDIZATION
MAGNETIC RESONANCE
MAPPING
MICROORGANISMS
OXIDOREDUCTASES
PROGRESS REPORT
REDOX POTENTIAL
RESONANCE
SPECTROSCOPY
STRUCTURAL CHEMICAL ANALYSIS
SYNTHESIS