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A U⋅U Pair‐to‐U⋅C Pair Mutation‐Induced RNA Native Structure Destabilisation and Stretching‐Force‐Induced RNA Misfolding
Author(s) -
Zhong Zhensheng,
Soh Lai Huat,
Lim Ming Hui,
Chen Gang
Publication year - 2015
Publication title -
chempluschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.801
H-Index - 61
ISSN - 2192-6506
DOI - 10.1002/cplu.201500144
Subject(s) - destabilisation , rna , chemistry , folding (dsp implementation) , kinetics , crystallography , molecular dynamics , hydrogen bond , biophysics , native state , optical tweezers , protein folding , mutation , base pair , stereochemistry , dna , physics , biology , biochemistry , computational chemistry , molecule , psychology , social psychology , organic chemistry , quantum mechanics , electrical engineering , gene , engineering
Little is known about how a non‐Watson–Crick pair affects the RNA folding dynamics. We studied the effects of a U⋅U‐to‐U⋅C pair mutation on the folding of a hairpin in human telomerase RNA. The ensemble thermal melting of the hairpins shows an on‐pathway intermediate with the disruption of the internal loop structure containing the U⋅U/U⋅C pairs. By using optical tweezers, we applied a stretching force on the terminal ends of the hairpins to probe directly the non‐nearest‐neighbour effects upon the mutations. The single U⋅U to U⋅C mutations are observed to 1) lower the mechanical unfolding force by approximately 1 picoNewton (pN) per mutation without affecting the unfolding reaction transition‐state position (thus suggesting that removing a single hydrogen bond affects the structural dynamics at least two base pairs away), 2) result in more frequent misfolding into a small hairpin at approximately 10 pN and 3) shift the folding reaction transition‐state position towards the native hairpin structure and slightly increase the mechanical folding kinetics (thus suggesting that untrapping from the misfolded state is not the rate‐limiting step).