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. 1982 Nov 11;10(21):7027–7039. doi: 10.1093/nar/10.21.7027

Evidence for tautomerism in nucleic acid base pairs. 1H NMR study of 15N labeled tRNA.

H Rüterjans, E Kaun, W E Hull, H H Limbach
PMCID: PMC326983  PMID: 7177856

Abstract

The imino proton resonances of 15N labeled tRNA appear as asymmetric doublet signals, the asymmetry being dependent on the applied magnetic field strength. Assuming a tautomerism of the type N-H...N not equal to N...H-N in the base pairs the line shapes can be simulated. The most important parameters fitted in the simulation are the rate constants of the proton transfer and the mole fractions of either tautomeric state. The rate constants are of the order of 100s-1 and the mole fractions of the non dominant tautomer about 0.1 depending on the temperature and on the nature of the base pairing. The observations are attributed to a double proton transfer in the base pairs. The unexpectedly slow rates of the double proton transfer process may be connected with a concomitant conformational change of the duplex structure.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

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