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-002966nas a2200229   4500008004100000022001400041245008000055210006900135260009000204300001200294490000800306520214900314653002102463653000802484653002802492653001202520653002102532100002602553700002802579700002802607856010102635       2010                        eng d  a0022-283600aIncrease in backbone mobility of the VTS1p-SAM domain on binding to SRE-RNA0 aIncrease in backbone mobility of the VTS1pSAM domain on binding   a24-28 OVAL RD, LONDON NW1 7DX, ENGLANDbACADEMIC PRESS LTD- ELSEVIER SCIENCE LTDcFEB  a732-7460 v3963 a<p>The sterile alpha motif (SAM) domain of VTS1p, a posttranscriptional gene regulator, belongs to a family of SAM domains conserved from yeast to humans. Even though SAM domains were originally classified as protein-protein interaction domains, recently, it was shown that the yeast VTS1p-SAM and the SAM domain of its Drosophila homolog Smaug can specifically recognize RNA hairpins termed Smaug recognition element (SRE). Structural studies of the SRE-RNA complex of VTS1p-SAM revealed that the SAM domain primarily recognizes the shape of the RNA fold induced by the Watson-Crick base-pairing in the RNA pentaloop. Only the central G nucleotide is specifically recognized. The VTS1p-SAM domain recognizes SRE-RNAs with a CNGGN pentaloop where N is any nucleotide. The C1-G4 base pair in the wild type can be replaced by any pair of nucleotides that can form base pairs even though the binding affinity is greatest with a pyrimidine in position 1 and a purine in position 4. The interaction thus combines elements of sequence-specific and non-sequence-specific recognitions. The lack of structural rearrangements in either partner following binding is rather intriguing, suggesting that molecular dynamics may play an important role in imparting relaxed specificity with respect to the exact combination of nucleotides in the loop, except for the central nucleotide. In this work, we extend our previous studies of SRE-RNA interaction with VTS1p, by comparing the dynamics of the VTS1p-SAM domain both in its free form and when bound to SRE-RNA. The 1 5 N relaxation studies of backbone dynamics suggest the presence of a dynamic interaction interface, with residues associated with specific G3 recognition becoming more rigid on RNA binding while other regions attain increased flexibility. The results parallel the observations from our studies of dynamics changes in SRE-RNA upon binding to VTS1p-SAM and shows that molecular dynamics could play a crucial role in modulating binding affinity and possibly contribute to the free energy of the interaction through an entropy-driven mechanism. (C) 2009 Elsevier Ltd. All rights reserved.</p>10a(15)N relaxation10aNMR10aprotein-RNA interaction10aSRE-RNA10aVTS1p-SAM domain1 aRavindranathan, Sapna1 aOberstrass, Florian, C.1 aAllain, Frederic, H. T.  uhttps://library.ncl.res.in/content/increase-backbone-mobility-vts1p-sam-domain-binding-sre-rna-000878nas a2200229   4500008004100000022001400041245008600055210006900141260010600210300000900316490000700325653001300332653002100345653002400366653002800390100002100418700002000439700001800459700002600477700002800503856011700531       2011                        eng d  a0079-656500aStructure determination and dynamics of protein-RNA complexes by NMR spectroscopy0 aStructure determination and dynamics of proteinRNA complexes by   aTHE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLANDbPERGAMON-ELSEVIER SCIENCE LTDcFEB  a1-610 v5810aDynamics10aNMR spectroscopy10aProtein-RNA complex10aStructure determination1 aDominguez, Cyril1 aSchubert, Mario1 aDuss, Olivier1 aRavindranathan, Sapna1 aAllain, Frederic, H. T.  uhttps://library.ncl.res.in/content/structure-determination-and-dynamics-protein-rna-complexes-nmr-spectroscopy-0