Editing Base pair (section)

==Base analogs and intercalators==

{{Main|Nucleic acid analogue}}
Chemical analogs of nucleotides can take the place of proper nucleotides and establish non-canonical base-pairing, leading to errors (mostly [[point mutation]]s) in [[DNA replication]] and [[Transcription (genetics)|DNA transcription]]. This is due to their [[isosteric]] chemistry. One common mutagenic base analog is [[5-bromouracil]], which resembles thymine but can base-pair to guanine in its [[enol]] form.<ref>{{cite journal | vauthors = Trautner TA, Swartz MN, Kornberg A | title = Enzymatic synthesis of deoxyribonucleic acid. X. Influence of bromouracil substitutions on replication | journal = Proceedings of the National Academy of Sciences of the United States of America | volume = 48 | issue = 3 | pages = 449–455 | date = March 1962 | pmid = 13922323 | pmc = 220799 | doi = 10.1073/pnas.48.3.449 | name-list-style = vanc | doi-access = free }}</ref>

Other chemicals, known as [[DNA intercalation|DNA intercalators]], fit into the gap between adjacent bases on a single strand and induce [[frameshift mutation]]s by "masquerading" as a base, causing the DNA replication machinery to skip or insert additional nucleotides at the intercalated site. Most intercalators are large [[polyaromatic]] compounds and are known or suspected [[carcinogen]]s. Examples include [[ethidium bromide]] and [[acridine]].<ref>{{Cite book | vauthors = Krebs JE, Goldstein ES, Kilpatrick ST, Lewin B |title=Lewin's genes XII |publisher=Jones & Bartlett Learning |year=2018 |isbn=978-1-284-10449-3 |edition=12th |location=Burlington, Mass |page=12 |chapter=Genes are DNA and Encode RNAs and Polypeptides |quote=Each mutagenic event in the presence of an acridine results in the addition or removal of a single base pair.}}</ref>{{citation needed|date=August 2022}}