Michael A Funk

Learn More
Anaerobic degradation of the environmental pollutant toluene is initiated by the glycyl radical enzyme benzylsuccinate synthase (BSS), which catalyzes the radical addition of toluene to fumarate, forming benzylsuccinate. We have determined crystal structures of the catalytic α-subunit of BSS with its accessory subunits β and γ, which both bind a [4Fe-4S](More)
The class III anaerobic ribonucleotide reductases (RNRs) studied to date couple the reduction of ribonucleotides to deoxynucleotides with the oxidation of formate to CO2. Here we report the cloning and heterologous expression of the Neisseria bacilliformis class III RNR and show that it can catalyze nucleotide reduction using the ubiquitous(More)
Various bacteria perform anaerobic degradation of small hydrocarbons as a source of energy and cellular carbon. To activate non-reactive hydrocarbons such as toluene, enzymes conjugate these molecules to fumarate in a radical-catalyzed, C-C bond-forming reaction. We have determined x-ray crystal structures of the glycyl radical enzyme that catalyzes the(More)
Heterotrimeric G proteins (Galphabetagamma) transmit signals from activated G protein-coupled receptors (GPCRs) to downstream effectors through a guanine nucleotide signaling cycle. Numerous studies indicate that the carboxy-terminal alpha5 helix of Galpha subunits participates in Galpha-receptor binding, and previous EPR studies suggest this(More)
Essential for DNA biosynthesis and repair, ribonucleotide reductases (RNRs) convert ribonucleotides to deoxyribonucleotides via radical-based chemistry. Although long known that allosteric regulation of RNR activity is vital for cell health, the molecular basis of this regulation has been enigmatic, largely due to a lack of structural information about how(More)
Everninomicin is a highly modified octasaccharide that belongs to the orthosomycin family of antibiotics and possesses potent Gram-positive antibiotic activity, including broad-spectrum efficacy against multidrug resistant enterococci and Staphylococcus aureus. Among its distinctive structural features is a nitro sugar, l-evernitrose, analogues of which(More)
Ribonucleotide reductase (RNR) converts ribonucleotides to deoxyribonucleotides, a reaction that is essential for DNA biosynthesis and repair. This enzyme is responsible for reducing all four ribonucleotide substrates, with specificity regulated by the binding of an effector to a distal allosteric site. In all characterized RNRs, the binding of effector(More)
Ribonucleotide reductases (RNRs) catalyze nucleotide reduction via complex radical chemistry, providing deoxynucleotides for DNA synthesis in all domains of life. Many anaerobic bacteria and archaea contain the class III O2-sensitive RNR, and those that have been studied to date couple nucleotide reduction to formate oxidation. Here (pp. E3756–E3765) we(More)
Fluorinated tyrosines (FnY's, n = 2 and 3) have been site-specifically incorporated into E. coli class Ia ribonucleotide reductase (RNR) using the recently evolved M. jannaschii Y-tRNA synthetase/tRNA pair. Class Ia RNRs require four redox active Y's, a stable Y radical (Y·) in the β subunit (position 122 in E. coli), and three transiently oxidized Y's (356(More)
Glycyl radical enzymes (GREs) are important biological catalysts in both strict and facultative anaerobes, playing key roles both in the human microbiota and in the environment. GREs contain a backbone glycyl radical that is post-translationally installed, enabling radical-based mechanisms. GREs function in several metabolic pathways including mixed acid(More)