Sökning: "ribonucleotide reductase"

Visar resultat 21 - 25 av 77 avhandlingar innehållade orden ribonucleotide reductase.

  1. 21. Structural and functional studies on ribonucleotide reductase protein B2 from Escherichia coli

    Författare :Margareta Karlsson; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Ribonucleotide reductases; Eshcerichia coli;

    Sammanfattning : Ribonucleotide reductase catalyzes the reduction of ribonucleotidesto the corresponding deoxyribonucleotides, the building blocks forDNA. The enzyme from Escherichia coli consists of two proteins.Bl and B2. Protein B2 contains two dinuclear iron centers and astable tyrosyl radical. LÄS MER

  3. 22. Theoretical Modeling of Enzyme Catalysis with Focus on Radical Chemistry

    Författare :Vladimir Pelmenschikov; Per E. M. Siegbahn; Tim Clark; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; density functional theory; enzyme catalysis; radical chemistry; zinc-containing peptidase; methyl-coenzyme M reductase; ribonucleotide reductase; superoxide dismutase; Quantum chemistry; Kvantkemi;

    Sammanfattning : Hybrid density functional theory (DFT) B3LYP method is applied to study the four diverse enzyme systems: zinc-containing peptidases (thermolysin and stromelysin), methyl-coenzyme M reductase, ribonucleotide reductases (classes I and III), and superoxide dismutases (Cu,Zn- and Ni-dependent enzymes). Powerfull tools of modern quantum chemistry are used to address the questions of biological pathways at their molecular level, proposing a novel mechanism for methane production by methyl-coenzyme M reductase and providing additional insights into hydrolysis by zinc peptidases, substrate conversion by ribonucleotide reductases, and biological superoxide dismutation. LÄS MER

  4. 23. The influence of nucleotides on ribonucleotide reductase assambly in class I ribonucleotide reductase from Escherichia coli

    Författare :Pernilla Larsson Birgander; Britt-Marie Sjöberg; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Molecular biology; Molekylärbiologi;

    Sammanfattning : The components of DNA, the deoxyribonucleotides, are produced from the components of RNA, the ribonucleotides. One single substitution is needed to convert a ribonucleotide into a deoxyribonucleotide i.e. a replacement of a hydroxyl group with a hydrogen atom. LÄS MER

  5. 24. Radical generation and stabilisation in ribonucleotide reductase R2

    Författare :Martin Högbom; Lawrence Que; Stockholms universitet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Biochemistry; Biokemi; Biochemistry; biokemi;

    Sammanfattning : Diiron carboxylate proteins contain a cofactor that consists of two iron atoms coordinated by carboxylate and histidine ligands. These proteins perform a multitude of chemical reactions in the cell that generally involve activation of molecular oxygen at the diiron site. LÄS MER

  7. 25. Radical transfer in ribonucleotide reductase from Escherichia coli

    Författare :Monica Ekberg; Janos Hajdu; Stockholms universitet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Molecular Biology; molekylärbiologi;

    Sammanfattning : .... LÄS MER