Local Structural and Environmental Factors Define the Efficiency of an RNA Pseudoknot Involved in Programmed Ribosomal Frameshift Process

Gupta, Asmita and Bansal, Manju (2014) Local Structural and Environmental Factors Define the Efficiency of an RNA Pseudoknot Involved in Programmed Ribosomal Frameshift Process. In: JOURNAL OF PHYSICAL CHEMISTRY B, 118 (41). pp. 11905-11920.

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Abstract

In programmed -1 ribosomal frameshift, an RNA pseudoknot stalls the ribosome at specific sequence and restarts translation in a new reading frame. A precise understanding of structural characteristics of these pseudoknots and their PRF inducing ability has not been clear to date. To investigate this phenomenon, we have studied various structural aspects of a -1 PRF inducing RNA pseudoknot from BWYV using extensive molecular dynamics simulations. A set of functional and poorly functional forms, for which previous mutational data were available, were chosen for analysis. These structures differ from each other by either single base substitutions or base-pair replacements from the native structure. We have rationalized how certain mutations in RNA pseudoknot affect its function; e.g., a specific base substitution in loop 2 stabilizes the junction geometry by forming multiple noncanonical hydrogen bonds, leading to a highly rigid structure that could effectively resist ribosome-induced unfolding, thereby increasing efficiency. While, a CG to AU pair substitution in stem 1 leads to loss of noncanonical hydrogen bonds between stems and loop, resulting in a less stable structure and reduced PRF inducing ability, inversion of a pair in stem 2 alters specific base-pair geometry that might be required in ribosomal recognition of nucleobase groups, negatively affecting pseudoknot functioning. These observations illustrate that the ability of an RNA pseudoknot to induce -1 PRF with an optimal rate depends on several independent factors that contribute to either the local conformational variability or geometry

Item Type:	Journal Article
Publication:	JOURNAL OF PHYSICAL CHEMISTRY B
Publisher:	AMER CHEMICAL SOC
Additional Information:	Copy right for this article belongs to the AMER CHEMICAL SOC, 1155 16TH ST, NW, WASHINGTON, DC 20036 USA
Department/Centre:	Division of Biological Sciences > Molecular Biophysics Unit
Date Deposited:	28 Nov 2014 04:53
Last Modified:	28 Nov 2014 04:53
URI:	http://eprints.iisc.ac.in/id/eprint/50330

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