THE DNA-SEQUENCE SPECIFICITY OF CYANOMORPHOLINOADRIAMYCIN

Cyanomorpholinoadriamycin (1-mu-M) was reacted in a transcription buffer with DNA of an initiated transcription complex. Subsequent elongation of the initiated complex revealed permanent transcriptional blockages at 16 sites after only 5 min of drug-DNA reaction time. The most dominant sites were immediately prior to 5'-CC (six) and 5'-GG (six) sequences of the non-template strand, consistent with the presence of intrastrand crosslinking between adjacent guanine residues. Minor levels of blockage were at 5'-GC and 5'-CG sequences and may reflect low levels of interstrand crosslinking.