A STRUCTURAL MOTIF IN THE VARIANT SURFACE GLYCOPROTEINS OF TRYPANOSOMA-BRUCEI
A STRUCTURAL MOTIF IN THE VARIANT SURFACE GLYCOPROTEINS OF TRYPANOSOMA-BRUCEI
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DOI：
10.1038/362603a0
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发表时间：
1993-04-15
期刊：
影响因子：
64.8
通讯作者：
WILEY, DC
中科院分区：
文献类型：
--
作者：
BLUM, ML;DOWN, JA;WILEY, DC
锥虫变体表面糖蛋白（VSG）ILTat 1.24的可变结构域已通过X射线晶体学显示与VSG MITat 1.2的结构非常相似，尽管它们的序列相似性很低。这些VSG的特定结构特征，包括碳水化合物取代α-螺旋，可以在其他VSG序列中找到。因此，锥虫中的抗原变异是通过序列变异而不是总体结构改变来实现的; VSG之间广泛的序列差异可能是另一个原因所必需的，例如避免被辅助T细胞识别。此外，发现VSG序列在VSG超家族内定义家族，其在锥虫基因组中进化。
The variable domain of the trypanosome variant surface glycoprotein (VSG) ILTat 1.24 has been shown by X-ray crystallography to resemble closely the structures of VSG MITat 1.2, despite their low sequence similarity. Specific structural features of these VSGs, including substitution of carbohydrate for an alpha-helix, can be found in other VSG sequences. Thus antigenic variation in trypanosomes is accomplished by sequence variation, not gross structural alteration; the extensive sequence differences among VSGs may be required for another reason, such as the avoidance of recognition by helper T cells. Additionally, VSG sequences are found to define families, within a VSG superfamily, which have evolved in the trypanosome genome.