1TVS

TRIFLUOROETHANOL STABILIZES A HELIX-TURN-HELIX MOTIF IN EQUINE INFECTIOUS-ANEMIA-VIRUS TRANS-ACTIVATOR PROTEIN

Summary for 1TVS

• Entry DOI: 10.2210/pdb1tvs/pdb
• Descriptor: TRANSACTIVATOR PROTEIN (1 entity in total)
• Functional Keywords: transcription regulation
• Biological source: Equine infectious anemia virus
• Cellular location: Host nucleus, host nucleolus : Q9WM01
• Total number of polymer chains: 1
• Total formula weight: 8466.57

Authors

Roesch, P.,Sticht, H. (deposition date: 1994-09-14, release date: 1994-11-30, Last modification date: 2024-10-23)

Primary citation

Sticht, H.,Willbold, D.,Ejchart, A.,Rosin-Arbesfeld, R.,Yaniv, A.,Gazit, A.,Rosch, P.
Trifluoroethanol stabilizes a helix-turn-helix motif in equine infectious-anemia-virus trans-activator protein.
Eur.J.Biochem., 225:855-861, 1994

PubMed Abstract: The solution structure of the 75-amino-acid trans-activator (Tat) protein of the equine infectious-anemia virus in trifluoroethanol-containing solution was determined by two-dimensional and three-dimensional nuclear magnetic resonance spectroscopy, resulting in a total of 838 nuclear-Over-hauser-enhancement distance restraints, and restrained molecular-dynamics simulations. In contrast to the recently determined structure of this protein in trifluoroethanol-free pH 6.3 solution, the hydrophobic core and the adjacent basic RNA-binding region of the protein showed well-defined alpha-helical secondary structure in trifluoroethanol-containing solution. The helical regions comprise those parts of the molecule whose helix-forming tendencies were noted earlier in trifluoroethanol-free solution. Two helices (Gln38-Arg43 and Asp48-Ala64) are connected by a tight type-II turn centered at the strictly conserved Gly46 leading to a helix-turn-helix motif in the core and basic region of the protein. A third helix (Thr9-Asn13) is located in the less well defined N-terminal part of the protein. These observations may support the notion that the protein adopts a helical structure in the RNA-binding region on complex formation. Although the secondary-structure elements become better defined in trifluoroethanol-containing solution, the opposite is true for the hydrophobically stabilized tertiary structure. This adds a caveat to studies of protein structures in trifluoroethanol-containing solution in general.

PubMed: 7957222
DOI: 10.1111/j.1432-1033.1994.0855b.x

Experimental method

SOLUTION NMR