Tautomeric equilibria of isoguanine and related purine analogs |
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Authors: | Nilesh B Karalkar Kshitij Khare Robert Molt |
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Institution: | 1. Foundation for Applied Molecular Evolution (FfAME), Alachua, FL, USA;2. Department of Statistics, University of Florida, Gainesville FL, USA;3. Department of Chemistry and Chemical Biology, Indiana University-Purdue University, Indianapolis, Indianapolis, IN, USA;4. ENSCO, Inc., Melbourne, FL, USA |
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Abstract: | Nucleobase pairs in DNA match hydrogen-bond donor and acceptor groups on the nucleobases. However, these can adopt more than one tautomeric form, and can consequently pair with nucleobases other than their canonical complements, possibly a source of natural mutation. These issues are now being re-visited by synthetic biologists increasing the number of replicable pairs in DNA by exploiting unnatural hydrogen bonding patterns, where tautomerism can also create mutation. Here, we combine spectroscopic measurements on methylated analogs of isoguanine tautomers and tautomeric mixtures with statistical analyses to a set of isoguanine analogs, the complement of isocytosine, the 5th and 6th “letters” in DNA. |
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Keywords: | Isoguanine isocytosine tautomer synthetic biology artificially expanded genetic information systems tautomeric ratios |
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