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Enzymatic Incorporation of a Coumarin–Guanine Base Pair
Author(s) -
Johnson Aaron,
Karimi Ashkan,
Luedtke Nathan W.
Publication year - 2019
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201910059
Subject(s) - chemistry , klenow fragment , nucleobase , guanine , deoxyribose , stereochemistry , base pair , dna , hydrogen bond , fluorescence , nucleotide , combinatorial chemistry , polymerase , molecule , biochemistry , physics , organic chemistry , quantum mechanics , exonuclease , gene
Previous expansions beyond nature's preferred base‐pairing interactions have utilized either nonpolar shape‐fitting interactions or classical hydrogen bonding. Reported here is a hybrid of these systems. By replacing a single N−H with C−H at a Watson–Crick interface, the design space for new drug candidates and fluorescent nucleobase analogues is dramatically expanded, as demonstrated here by the new, highly fluorescent deoxycytidine mimic 3‐glycosyl‐5‐fluoro‐7‐methoxy‐coumarin‐2′‐deoxyribose (d C C ). dGTP is selectively incorporated across from a template d C C during enzymatic DNA synthesis. Likewise, d C C is selectively incorporated across from a template guanine when d C C is provided as the triphosphate d C C TP . DNA polymerase I (Klenow fragment) exhibited about a 10‐fold higher affinity for d C C TP than dCTP, allowing selective incorporation of d C C in direct competition experiments. These results demonstrate that a single C−H can replace N−H at a Watson–Crick‐type interface with preservation of functional selectivity and enhanced activity.