title: Distinct conformational transition patterns of noncoding 7SK snRNA and HIV TAR RNAs upon Tat binding.
abstract: Noncoding 7SK snRNA is believed to play an important role in the recruitment of P-TEFb by viral protein Tat to stimulate HIV processive transcription. Because HIV-2 TAR RNA and 7SK both evolved to feature a dinucleotide bulge region, compared to the trinucleotide bulge for HIV-1 TAR, ultrafast time-resolved fluorescence spectroscopy has been used to probe the conformational landscape of HIV-2 TAR and 7SK-SL4 RNA to monitor the conformational changes upon Tat binding. Our studies demonstrate that both HIV-1/2 TAR and 7SK-SL4 sample heterogeneous ensembles in the free state and undergo distinct conformational transitions upon Tat binding. These findings provide exquisite knowledge on the conformational complexity and intricate mechanism of molecular recognition and pave the way for drug design and discovery that incorporate dynamics information.
authors.affiliation: Department of Molecular and Cell Biology, The University of Texas at Dallas , Richardson, Texas 75080, United States.
authors.forename: Jia
authors.initials: J
authors.lastname: Lu
authors.forename: Vivian
authors.initials: V
authors.lastname: Wong
authors.forename: Yi
authors.initials: Y
authors.lastname: Zhang
authors.forename: Trung
authors.initials: T
authors.lastname: Tran
authors.forename: Liang
authors.initials: L
authors.lastname: Zhao
authors.forename: Amy
authors.initials: A
authors.lastname: Xia
authors.forename: Tianbing
authors.initials: T
authors.lastname: Xia
authors.forename: Xin
authors.initials: X
authors.lastname: Qi
mesh_terms: D016325:HIV Long Terminal Repeat; D015497:HIV-1 / Q000378:metabolism*; D015498:HIV-2 / Q000378:metabolism*; D009690:Nucleic Acid Conformation; D011485:Protein Binding; D012342:RNA, Small Nuclear / Q000737:chemistry*; D012367:RNA, Viral / Q000737:chemistry* / Q000235:genetics; D017411:Ribonucleoproteins, Small Nuclear / Q000235:genetics*; D054322:tat Gene Products, Human Immunodeficiency Virus / Q000737:chemistry*
chemical_list: D012342:RNA, Small Nuclear; D012367:RNA, Viral; D017411:Ribonucleoproteins, Small Nuclear; D054322:tat Gene Products, Human Immunodeficiency Virus