01862nas a2200169   4500008004100000022001400041245007400055210006900129260007100198300001400269490000800283520123900291100002501530700002101555700001801576856009801594       2013                        eng d  a1520-610600aEffect of loops and G-quartets on the stability of RNA G-quadruplexes0 aEffect of loops and Gquartets on the stability of RNA Gquadruple  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcJUN  a6896-69050 v1173 a<p>The loop length, loop composition, salt concentration, and number of G-quartets are major determinants of G-quadruplex stability. We examined the effect of each of these factors on the thermal stability and folding topology of a library of RNA quadruplexes. The thermal stability of G2 and G3 RNA quadruplexes was investigated upon varying the loop length (from 1-1-1 to 15-15-15) and salt concentration (from sequence 1 to 100 mM KCl), while the effect of loop composition was explored using 18 naturally occurring potential RNA quadruplexes predicted in untranslated regions (UTRs). We found loop length and quadruplex stability to be inversely related for G2 RNA quadruplexes and G3 RNA quadruplexes with shorter loops. However, melting temperature saturates for G3 RNA quadruplexes with longer loops. RNA G-quadruplexes with longer loops (G3 15-15-15) displayed T-m values significantly higher than the physiological temperature. This study thus highlights the need to modify the consensus motif presently used by quadruplex prediction tools. An increase in the loop size from 7 bases to IS bases in the consensus motif will add to its predictive value for the discovery of potential RNA quadruplexes across transcriptomes.</p>1 aPandey, Satyaprakash1 aAgarwala, Prachi1 aMaiti, Souvik  uhttps://library.ncl.res.in/content/effect-loops-and-g-quartets-stability-rna-g-quadruplexes-0