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      https://www.ias.ac.in/article/fulltext/jbsc/032/05/0809-0825

    • Keywords

       

      Ab initio computation; hydrogen bond; interaction energy; noncanonical base pairs; RNA structure

    • Abstract

       

      Noncanonical base pairs in RNA have strong structural and functional implications but are currently not considered for secondary structure predictions. We present results of comparative ab initio studies of stabilities and interaction energies for the three standard and 24 selected unusual RNA base pairs reported in the literature. Hydrogen added models of isolated base pairs, with heavy atoms frozen in their ‘away from equilibrium’ geometries, built from coordinates extracted from NDB, were geometry optimized using HF/6-31G** basis set, both before and after unfreezing the heavy atoms. Interaction energies, including BSSE and deformation energy corrections, were calculated, compared with respective single point MP2 energies, and correlated with occurrence frequencies and with types and geometries of hydrogen bonding interactions. Systems having two or more N-H…O/N hydrogen bonds had reasonable interaction energies which correlated well with respective occurrence frequencies and highlighted the possibility of some of them playing important roles in improved secondary structure prediction methods. Several of the remaining base pairs with one N-H…O/N and/or one C-H…O/N interactions respectively, had poor interaction energies and negligible occurrences. High geometry variations on optimization of some of these were suggestive of their conformational switch like characteristics.

    • Author Affiliations

       

      Dhananjay Bhattacharyya1 Siv Chand Koripella2 Abhijit Mitra2 Vijay Babu Rajendran2 Bhabdyuti Sinha2

      1. Biophysics Division, Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata 700 064, India
      2. Center for Computational Natural Sciences and Bioinformatics, International Institute of Information Technology Gachibowli, Hyderabad 500 032, India
    • Dates

       
  • Journal of Biosciences | News

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