DNA-pyrimidine clusters isolated from Novikoff rat hepatoma cells labeled with [mefhyl-r4C]methionine were previously subfractionated on DEAE columns at acid PH. Each subfraction of differing over-all base composition was sequentially treated with Escherichia coli alkaline phosphatase and venom or bovine spleen phosphodiesterase. The resulting digests were analyzed for the quantity of 14C in th...

Tet family proteins have the ability to convert 5-methylcytosine (mC) to 5-hydroxymethylcytosine, and further to 5-formylcytosine and 5-carboxycytosine. We found that CGmCGCG can be the substrate of Tet protein, and observed iterative oxidation of mC by HPLC analysis. We also demonstrated that Tet protein favours single-stranded DNA over double-stranded DNA.

5-Formylcytosine (5fC) and 5-formyluracil (5fU) are natural nucleobase modifications that are generated by oxidative modification of 5-methylcytosine and thymine (or 5-methyluracil). Herein, we describe chemoselective labeling of 5-formylpyrimidine nucleotides in DNA and RNA by fluorogenic aldol-type condensation reactions with 2,3,3-trimethylindole derivatives. Mild and specific reaction condi...