To further define the structure and function of the domains in HIV-1 and SIV Tat proteins, chimeric Tat cDNA expression constructs were generated with crossover points at the carboxy-terminal end of the cysteine rich domain. The chimera containing the amino-terminal region of SIV and carboxy-terminal region of HIV exhibited activity similar to HIV-1 Tat and SIV Tat on both the HIV-1 and SIV LTRs. In contrast, the reciprocal chimera functioned poorly. As determined by the activity of carboxy-terminal truncation mutants, the region immediately downstream of the basic domain is critical for efficient transactivation by HIV-1 Tat, but not SIV Tat protein. In this report, we present a model for Tat domains based on NMR data and the known functional properties of Tat protein. According to our modeling two sites for protein : protein interactions are present in HIV-1 and SIV Tat proteins. Site I, which is presumably involved in cyclin T binding, is similar in both HIV-1 and SIV Tat proteins as well as in Tat chimeras. Site II, however appears structurally different in HIV-1 and SIV Tat models, although in both cases is comprised of amino and carboxy-terminal residues. Differences in Site II may thus account for the differential activities of HIV-1 and SIV Tat carboxy-terminal truncations. Site II in the poorly active chimera differs significantly from that found in HIV-1 and SIV Tat proteins. The two site structural model presented here may have important implications for the role of Tat in HIV pathogenesis and may provide insights for the design of Tat vaccines and targeted therapeutics.
An NMR-based scoring function improves the accuracy of binding pose predictions by docking by two orders of magnitude
An NMR-based scoring function improves the accuracy of binding pose predictions by docking by two orders of magnitude
Abstract Low-affinity ligands can be efficiently optimized into high-affinity drug leads by structure based drug design when atomic-resolution structural information on the protein/ligand complexes is available. In this work we show that the use of a few, easily obtainable, experimental restraints improves the accuracy of the docking experiments by two orders of magnitude. The experimental data are measured in nuclear magnetic resonance spectra and consist of...
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Structure-based prediction of methyl chemical shifts in proteins
Structure-based prediction of methyl chemical shifts in proteins
Abstract Protein methyl groups have recently been the subject of much attention in NMR spectroscopy because of the opportunities that they provide to obtain information about the structure and dynamics of proteins and protein complexes. With the advent of selective labeling schemes, methyl groups are particularly interesting in the context of chemical shift based protein structure determination, an approach that to date has exploited primarily the mapping between protein structures and backbone chemical shifts. In order to...
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07-15-2011 09:10 PM
Exclusively NOESY-based automated NMR assignment and structure determination of proteins
Exclusively NOESY-based automated NMR assignment and structure determination of proteins
Abstract A fully automated method is presented for determining NMR solution structures of proteins using exclusively NOESY spectra as input, obviating the need to measure any spectra only for obtaining resonance assignments but devoid of structural information. Applied to two small proteins, the approach yielded structures that coincided closely with conventionally determined structures.
Content Type Journal Article
Pages 1-10
DOI 10.1007/s10858-011-9502-8
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Exclusively NOESY-based automated NMR assignment and structure determination of proteins.
Exclusively NOESY-based automated NMR assignment and structure determination of proteins.
Exclusively NOESY-based automated NMR assignment and structure determination of proteins.
J Biomol NMR. 2011 Mar 30;
Authors: Ikeya T, Jee JG, Shigemitsu Y, Hamatsu J, Mishima M, Ito Y, Kainosho M, Güntert P
A fully automated method is presented for determining NMR solution structures of proteins using exclusively NOESY spectra as input, obviating the need to measure any spectra only for obtaining resonance assignments but devoid of structural information....
[NMR paper] Multidimensional NMR spectroscopy of DNA-binding proteins: structure and function of
Multidimensional NMR spectroscopy of DNA-binding proteins: structure and function of a transcription factor.
Related Articles Multidimensional NMR spectroscopy of DNA-binding proteins: structure and function of a transcription factor.
Toxicol Lett. 1995 Dec;82-83:577-89
Authors: Hsu VL, Jia X, Kearns DR
The solution structure of a type II DNA-binding protein (DBPII), transcription factor 1 (TF1), has been determined using NMR spectroscopy. A multidimensional, heteronuclear strategy was employed to overcome assignment ambiguities due to...
Structure and function of HIV-1 and SIV Tat proteins based on carboxy-terminal trunca
Linear Mode
