RNA hydrolysis via an oxyphosphorane intermediate.

T Uchimaru; J W Storer; K Tanabe; M Uebayasi; S Nishikawa; K Taira

doi:10.1016/0006-291x(92)90475-z

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RNA hydrolysis via an oxyphosphorane intermediate.

T Uchimaru·J W Storer·K Tanabe·M Uebayasi·S Nishikawa·K Taira

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Abstract

From calculations of a model reaction scheme for base-catalyzed RNA hydrolysis, a pentacoodinate dianionic intermediate 2a (Storer, et al., J. Am. Chem. Soc., 1991, 113, 5216-5219) as well as two transition states, TS1 and TS2, to the intermediate have been located by ab initio calculations at the 3-21G* level. Although the intermediate, which has the well depth on the order of kBT, is unlikely to be kinetically significant, the overall rate-limiting transition state structure TS2 obtained at 3-21G* level is very close to the corresponding structure at the STO-3G level; it has an extended P-O(5') bond breaking character. These gas-phase calculation results are used to qualitatively interpret mutagenesis results of Barnase and RNase T1 where water molecules are absent from the active site.

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Bacterial Proteins Catalysis Hydrogen-Ion Concentration Hydrolysis Models, Molecular RNA Ribonuclease T1 Ribonucleases Thermodynamics Journal Article Research Support, Non-U.S. Gov't

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T Uchimaru, J W Storer, K Tanabe, M Uebayasi, S Nishikawa, K Taira. 1992-09-30. RNA hydrolysis via an oxyphosphorane intermediate.. https://doi.org/10.1016/0006-291x(92)90475-z

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