title: 1H-13C nuclear magnetic resonance assignment and structural characterization of HIV-1 Tat protein.
abstract: Tat is a viral protein essential for activation of the HIV genes and plays an important role in the HIV-induced immunodeficiency. We chemically synthesized a Tat protein (86 residues) with its six glycines C alpha labelled with 13C. This synthetic protein has the full Tat activity. Heteronuclear nuclear magnetic resonance (NMR) spectra and NOE back-calculation made possible the sequential assignment of the 86 spin systems. Consequently, 915 NMR restraints were identified and 272 of them turned out to be long range ([i-j] > 4), providing structural information on the whole Tat protein. The poor spectral dispersion of Tat NMR spectra does not allow an accurate structure to be determined as for other proteins studied by 2D NMR. Nevertheless, we were able to determine the folding for Tat protein at a 1-mM protein concentration in a 100 mM, pH 4.5 phosphate buffer. The two main Tat functional regions, the basic region and the cysteine-rich region, are well exposed to solvent while a part of the N-terminal region and the C-terminal region constitute the core of Tat Bru. The basic region adopts an extended structure while the cysteine-rich region is made up of two loops. Resolution of this structure was determinant to develop a drug design approach against Tat. The chemical synthesis of the drugs allowed the specific binding and the inhibition of Tat to be verified.
authors.affiliation: Laboratoire d'ingéniérie des systèmes macromoléculaires, Institut de biologie structurale et microbiologie, Marseilles, France.
authors.forename: J M
authors.initials: JM
authors.lastname: Péloponèse
authors.forename: C
authors.initials: C
authors.lastname: Grégoire
authors.forename: S
authors.initials: S
authors.lastname: Opi
authors.forename: D
authors.initials: D
authors.lastname: Esquieu
authors.forename: J
authors.initials: J
authors.lastname: Sturgis
authors.forename: E
authors.initials: E
authors.lastname: Lebrun
authors.forename: E
authors.initials: E
authors.lastname: Meurs
authors.forename: Y
authors.initials: Y
authors.lastname: Collette
authors.forename: D
authors.initials: D
authors.lastname: Olive
authors.forename: A M
authors.initials: AM
authors.lastname: Aubertin
authors.forename: M
authors.initials: M
authors.lastname: Witvrow
authors.forename: C
authors.initials: C
authors.lastname: Pannecouque
authors.forename: E
authors.initials: E
authors.lastname: De Clercq
authors.forename: C
authors.initials: C
authors.lastname: Bailly
authors.forename: J
authors.initials: J
authors.lastname: Lebreton
authors.forename: E P
authors.initials: EP
authors.lastname: Loret
mesh_terms: D000595:Amino Acid Sequence; D015696:Gene Products, tat / Q000737:chemistry*; D015497:HIV-1 / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011487:Protein Conformation; D054322:tat Gene Products, Human Immunodeficiency Virus
chemical_list: D015696:Gene Products, tat; D054322:tat Gene Products, Human Immunodeficiency Virus