Accession Number : ADA328613

Title :   Metabolic and Enzymological Studies of Sulfur-Dependent Marine Hyperthermophiles.

Descriptive Note : Final rept. Jun 93-May 96,

Corporate Author : GEORGIA UNIV RESEARCH FOUNDATION INC ATHENS

Personal Author(s) : Adams, Michael w.

PDF Url : ADA328613

Report Date : SEP 1996

Pagination or Media Count : 9

Abstract : The results from this study have provided the first insights into how hyperthermophilic organisms obtain energy from the metabolism of C and N compounds, and how this can be achieved at high temperatures. These organisms have unusual pathways based on the rarely-used element tungsten (W), which is present in the novel enzymes AOR, FOR and GAPOR. W is seldom used in biological systems, the analogous element, molybdenum (Mo), is virtually ubiquitous. We propose that W is much more suited to catalyze low potential reactions (such as those catalyzed by GAPOR, AOR and FOR) at extreme temperatures, and that such reactions could not be catalyzed by Mo-containing enzymes. We have cloned and sequenced the first genes for any W-protein, and the first genes for hyperthermophilic oxidoreductases. In addition, a new pathway for peptide metabolism as been proposed, again involving new types of enzyme, such as VOR, IOR and ACS. We also provided the first definitive model for the evolution of mesophilic oxidoreductases from hyperthermophilic enzymes, and the first crystal structure for a hyperthermophilic enzyme (AOR) was obtained, providing the first insights in to protein stability at extreme temperatures.

Descriptors :   *ENZYMES, *METABOLISM, *MICROORGANISMS, STABILITY, PEPTIDES, HIGH TEMPERATURE, PROTEINS, CATALYSTS, GENES, CLONES, OXIDOREDUCTASES, ANAEROBIC PROCESSES, THERMOPHILIC FUNGUS.

Subject Categories : Biochemistry
      Genetic Engineering and Molecular Biology
      Microbiology

Distribution Statement : APPROVED FOR PUBLIC RELEASE