Inhibition of bacterial DNA cytosine-5-methyltransferase by S-adenosyl-L-homocysteine and some related compounds.

S-Adenosyl-L-homocysteine and five related compounds have been evaluated as inhibitors of a DNA cytosine-5-methyltransferase. DNA methylation was assayed in cell extracts from E. coli strain J6-2 dcm+, proficient in DNA cytosine-5-methyltransferase activity, containing substrate DNA isolated from E.

Differentiation between mitochondrial and cytoplasmic protein subunits of blowfly flight muscle mitochondria synthesized in vivo.

Total adult blowfly flight-muscle mitochondrial protein was labelled in vivo with [14C]leucine. The labelled proteins were enumerated and characterized by their electrophoretic mobility using sodium dodcecyl sulphate/polyacrylamide gel electrophoresis and autoradiography. When different gel concentrations were used to resolve the maximum number of bands and their molecular weights, it was possible to observe at least 35 electrophoretic bands after staining and scanning; their molecular weights ranged between 11 000 and 130 000.

The respiration pathways of wild-type and petite mutants of Kluyveromyces lactis.

The existence of two alternative respiration pathways in Kluyveromyces lactis has been confirmed. Both pathways may be demonstrated in petite mutants of this yeast, suggesting that the major components in these pathways have an extramitochondrial origin. The antimycin A insensitive/sodium azide insensitive pathway (pathway I) is abolished by glucose repression of this yeast, whereas the antimycin A insensitive/sodium azide sensitive pathway (pathway II) is unaffected by this treatment.