9 items with the tag “hydrogenase

  • Structure, Function, and Biosynthesis of the Complex Iron-Sulfur Clusters at the Active Sites of Nitrogenases and Hydrogenases
    NAI 2009 Montana State University Annual Report

    Iron-sulfur clusters are thought to be among the most ancient cofactors in living systems. The iron-sulfur enzyme thrust is focused on examining the structure, mechanism, and biosynthesis of the complex Fe-S enzymes nitrogenase and hydrogenase. Biochemical, biophysical, and structure biology approaches are being employed to provide insights into complex iron-sulfur biosynthesis to establish paradigms for complex iron-sulfur cluster biosynthesis that can be placed in the context of the evolution of iron-sulfur motifs from the abiotic to biotic systems.

    ROADMAP OBJECTIVES: 3.1 3.2 3.3 6.1 6.2 7.1 7.2
  • Radical SAM Enzyme Functional Diversity and Evolution
    NAI 2010 Montana State University Annual Report

    The role of radical generating iron-sulfur enzymes in making modification to iron-sulfur motifs in biology are key to the maturation of nitrogen fixing and hydrogen oxidizing enyzme activities. These enzymes act through a mechanism analogous to what has been termed ligand assisted catalysis in discussions of tuning the reactivity of iron sulfur mineral motifs before the advent of life. This strong parallel between biological and abiotic processes provides a basis to better understand the transition from prebiotic chemistry to biochemistry or the transition from the nonliving to the living EArth.

    ROADMAP OBJECTIVES: 3.1 3.2 3.3 3.4
  • Structure, Reactivity, and Biosynthesis of Cataylic Iron-Sulfur Clusters
    NAI 2010 Montana State University Annual Report

    We are examining the biosynthesis of complex iron-sulfur cluster to determine the specific chemistry associated with modifying iron-sulfur motifs in biology for different functions. We then relate the chemistry associated with these modifying reactions to reactions that could potentially modify iron-sulfur mineral motifs in the early non-living Earth to promote analogous reactivity.

    ROADMAP OBJECTIVES: 3.1 3.2 3.3 3.4 4.1 7.1 7.2
  • Paradigms for Complex Iron-Sulfur Cluster Assembly and the Origin and Evolution of Iron-Sulfur Enzymes
    NAI 2011 Montana State University Annual Report

    We have presented seminal results in the past year that define paradigms for iron-sulfur cluster assembly in biology that are shared between several important enzymes systems. This work has allowed for the formulation of new models for the origin and evolution of iron sulfur enzymes. An evolutionary origin that involves a mineral beginning and the stepwise refinement of catalytic function in response to selective pressure.

    ROADMAP OBJECTIVES: 3.1 3.2 3.3
  • Radical SAM Chemistry and Biological Ligand Accelerated Catalysis
    NAI 2011 Montana State University Annual Report

    A number of key reactions in biological systems are catalyzed by iron-sulfur enzymes. Iron-sulfur clusters in biology have a number of features in common with iron-sulfur minerals and their derivatives. We are using iron sulfur motifs as a model system to understand how chemistry in the abiotic mineral world was incorporated into biology on a path to the origin of life. We have found that iron-sulfur motifs in biology are synthesized and modified by reactions and mechanisms that we envision minerals could have been modified on the early prebiotic Earth. The results have had a profound impact on our ability to understand a stepwise trajectory from the nonliving to the living Earth.

    ROADMAP OBJECTIVES: 3.1 3.2 3.3
  • Molecular Evolution: A Top Down Approach to Examine the Origin of Key Biochemical Processes
    NAI 2011 Montana State University Annual Report

    The emergence of metalloenzymes capable of activating substrates such as CO, N2, and H2, were significant advancements in biochemical reactivity and in the evolution of complex life. Examples of such enzymes include [FeFe]- and [NiFe]-hydrogenase that function in H2 metabolism, Mo-, V-, and Fe-nitrogenases that function in N2 reduction, and CO dehydrogenases that function in the oxidation of CO. Many of these metalloenzymes have closely related paralogs that catalyze distinctly different chemistries, an example being nitrogenase and its closely related paralog protochlorophyllide reductase that functions in the biosynthesis of bacteriochlorophyll (photosynthesis). While the amino acid composition of these closely related paralogs are often quite similar, their biochemical reactivity and substrate specificity are often very different. This phenomenon is a direct consequence of the composition and molecular structure of the active site metallocluster, which requires a number of accessory proteins to synthesize. By specifically focusing on the origin and subsequent evolution of these metallocluster biosynthesis proteins in relation to paralogous proteins that have left clear evidence in the geological record (photosynthesis and the rise of O2), we have been able to obtain significant insight into the origin and evolution of these functional processes, and to place these events in evolutionary time.

    The genomes of extant organisms provide detailed histories of key events in the evolution of complex biological processes such as CO, N2, and H2 metabolism. Advances in sequencing technology continue to increase the pace by which unique (meta)genomic data is being generated. This now makes it possible to seamlessly integrate genomic information into an evolutionary context and evaluate key events in the evolution of biological processes (e.g., gene duplications, fusions, and recruitments) within an Earth history framework. Here we describe progress in using such approaches in examining the evolution of CO, N2, and H2 metabolism.

    ROADMAP OBJECTIVES: 3.2 4.1 5.1
  • Radical SAM Chemistry and Biological Ligand Accelerated Catalysis
    NAI 2012 Montana State University Annual Report

    Iron sulfur (FeS) clusters are thought to be among the most ancient cofactors in living systems. The FeS enzyme thrust is focused on examining the structure, mechanism, and biosynthesis of the complex FeS enzymes nitrogenase and hydrogenase. Exciting recent results have identified important links between the biosynthesis of the H-cluster and FeMo-co and have outlined a new paradigm for the biosynthesis of complex FeS clusters. The observations made have provided direct links to the evolution of FeS biocatalysts from their mineral-based precursors.

    ROADMAP OBJECTIVES: 3.1 3.2 3.3 7.1 7.2
  • Molecular Evolution: A Top Down Approach to Examine the Origin of Key Biochemical Processes
    NAI 2012 Montana State University Annual Report

    The emergence of metalloenzymes capable of activating substrates such as CO, N2, and H2, were significant advancements in biochemical reactivity and in the evolution of complex life. Examples of such enzymes include [FeFe]- and [NiFe]-hydrogenase that function in H2 metabolism, Mo-, V-, and Fe-nitrogenases that function in N2 reduction, and CO dehydrogenases that function in the oxidation of CO. Many of these metalloenzymes have closely related paralogs that catalyze distinctly different chemistries, an example being nitrogenase and its closely related paralog protochlorophyllide reductase that functions in the biosynthesis of bacteriochlorophyll (photosynthesis). By specifically focusing on the origin and subsequent evolution of these metallocluster biosynthesis proteins in relation to paralogous proteins that have left clear evidence in the geological record (photosynthesis and the rise of O2), we have been able to obtain significant insight into the origin and evolution of these functional processes, and to place these events in evolutionary time.

    The genomes of extant organisms provide detailed histories of key events in the evolution of complex biological processes such as CO, N2, and H2 metabolism. Advances in sequencing technology continue to increase the pace by which unique (meta)genomic data is being generated. This now makes it possible to seamlessly integrate genomic information into an evolutionary context and evaluate key events in the evolution of biological processes (e.g., gene duplications, fusions, and recruitments) within an Earth history framework. Here we describe progress in using such approaches in examining the evolution of CO, N2, and H2 metabolism.

    ROADMAP OBJECTIVES: 3.2 4.1 5.1