Hartmut Follmann

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Oxidized thioredoxin undergoes sulfitolysis of its single disulfide bond at low concentrations of sulfite ions and protein and in the absence of denaturing agents. The reaction, which has an optimum at pH 8, was studied using [35S]sulfite and E. coli thioredoxin as model. The product, thioredoxin-S-sulfonate, has a half-life of several hours in solution. It(More)
Ribonucleotide reduction and not DNA replication is the site for the specific manganese requirement of DNA synthesis and cell growth in the coryneform bacterium Brevibacterium ammoniagenes. To characterize the metal effect we have isolated and purified ribonucleoside-diphosphate reductase from overproducing bacteria that were first deprived of and then(More)
In many physiological studies dehydroascorbate (DHA) reductase is regarded as one of the chloroplast enzymes involved in the protection against oxidative stress. Here, evidence is presented that plant cells do not possess a specific DHA reductase. The DHA reductase activities measured in plant extracts are due to side reactions of proteins containing(More)
A gene has been cloned from Trypanosoma brucei which encodes a protein of 144 amino acid residues containing the thioredoxin-like motif WCPPCR. Overexpression of the gene in E. coli resulted in 4 mg pure protein from 100 ml bacterial cell culture. Recombinant T. brucei tryparedoxin acts as a thiol-disulfide oxidoreductase. It is spontaneously reduced by(More)
The origin and function of the large amount of 5-methylcytosine in plant DNA is not well understood. As a tool for in vitro studies of methylcytosine formation in plants we have isolated and characterized the DNA methyltransferase present in germinating wheat embryo. An enzyme fraction enriched 300-fold over the tissue homogenate was obtained by salt(More)
The pyruvate and alpha-ketoglutarate dehydrogenase complexes isolated from pig heart mitochondria promote the reduction of thioredoxin in the presence of their alpha-ketoacid substrates, coenzyme A, and free lipoate. Substrate-specific generation of reduced thioredoxin was established by two independent methods, viz. reduction of insulin and thioredoxin(More)
The reduction of 2'-ribonucleotides to 2'-deoxyribonucleotides, a unique step in DNA formation, is catalyzed by ribonucleotide reductase (RRase), an allosterically regulated, cell cycle-dependent enzyme. This work reports a reversible impairment of DNA formation and ribonucleotide reduction upon manganese depletion in Bacillus subtilis demonstrated through(More)