Abstract: | A comparative study of the reactivities of free 5-hydroxymethylcytosine (5-HMC) and 5-HMC found in the composition of native, denaturated and intraphage DNA of the T2 phage with that of O-methylhydroxylamine (OMHA) demonstrated that the DNA secondary structure in situ is partially disturbed. The interaction DNA-protein in the phage particle channels the reaction into a predominant formation of 4N-methoxy-6-methoxyamino-5,6-dihydro-5-hydroxymethyl cytosine, but not 4N-methoxy-5-hydroxymethyl cytosine, which is formed in vitro. In the course of the reaction the interaction DNA-protein is probably fixed by covalent binding. |