Homonuclear (1)H-NMR assignment and structural characterization of human immunodeficiency virus type 1 Tat Mal protein.-猫眼课题宝

人类免疫缺陷病毒 1 型 Tat Mal 蛋白的同核 (1)H-NMR 归属和结构表征。

DOI：

10.1002/bip.10000

发表时间：

2001

期刊：

Biopolymers

影响因子：

2.9

通讯作者：

中科院分区：

生物学4区

文献类型：

作者：

C. Gregoire;J. Péloponèse;D. Esquieu;S. Opi;G. Campbell;M. Solomiac;E. Lebrun;J. Lebreton;E. Loret

反式转录激活因子(TAT)是人类免疫缺陷病毒(HIV)基因激活所必需的病毒蛋白，在HIV诱导的免疫缺陷中起重要作用。我们报道了活性Tat MAL变异体的核磁共振结构特征，该变异体属于主要在非洲发现的高毒力D亚型HIV-1(HIV-1)毒株(MAL)。合成了一个完整的TAT MAL蛋白(87个残基)。这种合成的蛋白质在感染了HIV-1前病毒(LTR)lac Z基因的长端重复非编码序列的HeLa细胞的反式激活试验中是活跃的。同核(1)氢-核磁共振谱允许顺序指认TAT MAL自旋系统。模拟退火产生了20个具有相似折叠的构象。通过能量最小化优化平均结构的几何形状，得到最终的结构。作为欧洲变异体(Tat Bru)，Tat Mal的N-末端区域构成了核心，并且有一个由保守的Trp 11与几个芳香族残基相互作用组成的疏水口袋。TAT的两个功能区(碱性和富含半胱氨酸的区域)很好地暴露在溶剂中。在与碱基区相邻的V区观察到一个短的α螺旋。与Tat Bru的核磁共振结构相比，这个α螺旋引起了局部结构变化，使富含半胱氨酸的区域和碱性区域更近。这项研究表明，TAT变异体之间存在类似的折叠。

The transacting transcriptional activator (Tat) is a viral protein essential for activation of the human immunodeficiency virus (HIV) genes, and it plays an important role in HIV induced immunodeficiency. We report the NMR structural characterization of the active Tat Mal variant that belongs to a highly virulent D-subtype HIV type-1 (HIV-1) strain (Mal) found mainly in Africa. A full Tat Mal protein (87 residues) is synthesized. This synthetic protein is active in a transactivation assay with HeLa cells infected with the HIV long terminal repeated noncoding sequences of the HIV-1 provirus (LTR) lac Z gene. Homonuclear (1)H-NMR spectra allows the sequential assignment of the Tat Mal spin systems. Simulating annealing generates 20 conformers with similar folding. The geometry of the mean structure is optimized with energy minimization to obtain a final structure. As the European variant (Tat Bru) the N-terminal region of Tat Mal constitutes the core, and there is a hydrophobic pocket composed of the conserved Trp 11 interacting with several aromatic residues. The two functional regions of Tat (basic and the cysteine-rich regions) are well exposed to the solvent. A short alpha-helix is observed in region V adjacent to the basic region. This alpha helix induces local structural variations compared to the NMR structure of Tat Bru, and it brings the cysteine-rich and basic regions closer. This study suggests that similar folding exists among Tat variants.