02106nas a2200169   4500008004100000022001400041245010100055210006900156260007100225300001600296490000800312520141500320100002801735700002801763700002601791856011901817       2008                        eng d  a0002-786300aChanges in dynamics of SRE-RNA on binding to the VTS1p-SAM domain studied by C-13 NMR relaxation0 aChanges in dynamics of SRERNA on binding to the VTS1pSAM domain   a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcSEP  a12007-120200 v1303 a<p>RNA recognition by proteins is often accompanied by significant changes in RNA dynamics in addition to conformational changes. However, there are very few studies which characterize the changes in molecular motions in RNA on protein binding. We present a quantitative C-13 NMR relaxation study of the changes in RNA dynamics in the pico-nanosecond time scale and micro-millisecond time scale resulting from interaction of the stem-loop SRE-RNA with the VTS1p-SAM domain. C-13 relaxation rates of the protonated carbons of the nucleotide base and anomeric carbons have been analyzed by employing the model-free formalism, for a fully C-13/N-15-labeled sample of the SRE-RNA in the free and protein-bound forms. In the free RNA, the nature of molecular motions are found to be distinctly different in the stem and the loop region. On binding to the protein, the nature of motions becomes more homogeneous throughout the RNA, with many residues showing increased flexibility at the aromatic carbon sites, while the anomeric carbon sites become more rigid. Surprisingly, we also observe indications of a slow collective motion of the RNA in the binding pocket of the protein. The observation of increased motions on binding is interesting in the context of growing evidence that binding does not always lead to motional restrictions and the resulting entropy gain could favor the free energy of association.</p>1 aOberstrass, Florian, C.1 aAllain, Frederic, H. T.1 aRavindranathan, Sapna  uhttps://library.ncl.res.in/content/changes-dynamics-sre-rna-binding-vts1p-sam-domain-studied-c-13-nmr-relaxation-0