Previous studies (1, 2) have demonstrated that resting cell suspensions of Escherichia coli B not only incorporate 2,6diaminopurine into 5’-nucleotides but also metabolize it to 2methylamino-6-aminopurine, which is then converted to 5’phosphoribosyl-2-methylamino-6-aminopurine. For methyldiaminopurine synthesis, crude, cell-free extracts of E. coli B require methionine,l ATP, Mg++, and diaminop...

Gas-liquid mass transfer of gaseous reactants is a major limitation for high space-time yields, especially for O2 -dependent (bio)catalytic reactions in aqueous solutions. Herein, oxygenic photosynthesis was used for homogeneous O2 supply via in situ generation in the liquid phase to overcome this limitation. The phototrophic cyanobacterium Synechocystis sp. PCC6803 was engineered to synthesize...

Human lymphoid cell lines contain a DNA repair enzyme which removes the mutagenic alkylation lesion O6-methylguanine from DNA. The enzyme transfers the methyl group to a protein cysteine residue, generating S-methylcysteine, and is inactivated as a consequence of the reaction. Apparently the methylated enzyme represents a dead-end complex. The transfer reaction is very rapid and is completed in...

Methyl-transverse relaxation optimized spectroscopy is rapidly becoming the preferred NMR technique for probing structure and dynamics of very large proteins up to ~1 MDa in molecular size. Data interpretation, however, necessitates assignment of methyl groups which still presents a very challenging and time-consuming process. Here we demonstrate that, in combination with a known 3D structure, ...

The general features are known for the pathway by which most methane is produced in nature. All acetate-utilizing methanogenic microorganisms contain CODH which catalyzes the cleavage of acetyl-CoA; however, the pathway differs from all other acetate-utilizing anaerobes in that the methyl group is reduced to methane with electrons derived from oxidation of the carbonyl group of acetyl-CoA to CO...

Three tricyclic vinylcyclobutanes (3-methylenetricyclo[5.3.0.0(2,6)]decanes 1-3) have been subjected to ionization by photoinduced electron transfer in solution and by X-irradiation in Ar matrices. All three compounds undergo oxidative cycloreversion; the cleavage of the four-membered ring, however, occurs in a different direction depending on the presence of a methyl group in position 6 of the...

A closely related family of enzymes from Mycobacterium tuberculosis has been shown by heterologous expression to catalyze the modification of mycolic acids through the addition of a methyl (or methylene) group derived from S-adenosyl-L-methionine (SAM). Overproduction of all six of these enzymes in Escherichia coli and subsequent in vitro reactions with heat-inactivated acceptor fractions deriv...