Figure 8.

Molecular structure of side-products that can potentially interfere with reverse transcription. Multiple UV damage lesions have been reported with the uracil cyclobutane dimer and 8-oxoguanine as the predominant ones. Pyrimidines can photo-cross-link to proteins, with cysteine and phenylalanine adducts as speculated products. Nitrogen mustards can cross-link nucleic acids to cysteine residues. It is expected that bifunctional acylators can cross-link RNA to nucleophilic residues (X) on proteins.