Sequence-specific resonance assignments of the 1H-NMR spectra of a synthetic, biologically active EIAV Tat protein.

The equine infectious anemia virus (EIAV) trans-activating (Tat) protein is a close homologue of the human immunodeficiency virus (HIV) Tat protein. Both of these proteins bind to an RNA transactivation responsive element (TAR). We synthesized chemically a protein with the sequence of the 75 amino acid Tat protein from EIAV. The chemically synthesized protein was shown to be biologically active. Circular dichroism (CD) and 1 H nuclear magnetic resonance (NMR) spectroscopy were used to structurally characterize the synthetic protein. We obtained nearly complete resonance assignments in the 2D-NMR spectra of the protein at pH 3.0