Unusual sugar specificity of banana lectin from Musa paradisiaca and its probable evolutionary origin. Crystallographic and modelling studies.
Unusual sugar specificity of banana lectin from Musa paradisiaca and its probable evolutionary origin. Crystallographic and modelling studies.
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来自 Musa paradisiaca 的香蕉凝集素的异常糖特异性及其可能的进化起源。
DOI：
10.1093/glycob/cwi087
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发表时间：
2005
期刊：
影响因子：
4.3
通讯作者：
Mamannamana Vijayan
中科院分区：
文献类型：
--
作者：
Desh Deepak Singh;K. Saikrishnan;Prashant Kumar;A. Surolia;Kanagaraj Sekar;Mamannamana Vijayan
甲基-α-D-甘露糖苷与来自香蕉的香蕉凝集素的复合物的晶体结构揭示了凝集素中的两个主要结合位点，这与具有β-棱柱I折叠的其他凝集素不同，β-棱柱I折叠基本上由三个希腊关键基序组成。有人认为，褶皱是通过连续的基因复制和祖先希腊关键基序的融合而进化的。在其他凝集素中，所有来自双子叶植物，主要结合位点存在于三重对称分子中的三个基序之一上。香蕉是单子叶植物，这三个基序的差异还不足以消除它们之间的序列相似性。它的两个希腊关键基序各携带一个主要结合位点。一个共同的二级结合位点存在于第三个希腊键上。建模显示，两个一级位点都可以支持1-2、1-3和1-6个连接的甘露糖苷，其中第二个残基在每种情况下主要与二级结合位点相互作用。建模也很容易导致绑定分支甘露戊糖与锚定在两个主要结合位点的两个分支的非还原性末端，提供了一个结构解释的凝集素的特异性分支α-甘露聚糖。二聚体香蕉凝集素与其他β-棱镜我折叠凝集素的比较，提供了有趣的见解在其四级结构的变化。
The crystal structure of a complex of methyl-alpha-D-mannoside with banana lectin from Musa paradisiaca reveals two primary binding sites in the lectin, unlike in other lectins with beta-prism I fold which essentially consists of three Greek key motifs. It has been suggested that the fold evolved through successive gene duplication and fusion of an ancestral Greek key motif. In other lectins, all from dicots, the primary binding site exists on one of the three motifs in the three-fold symmetric molecule. Banana is a monocot, and the three motifs have not diverged enough to obliterate sequence similarity among them. Two Greek key motifs in it carry one primary binding site each. A common secondary binding site exists on the third Greek key. Modelling shows that both the primary sites can support 1-2, 1-3, and 1-6 linked mannosides with the second residue interacting in each case primarily with the secondary binding site. Modelling also readily leads to a bound branched mannopentose with the nonreducing ends of the two branches anchored at the two primary binding sites, providing a structural explanation for the lectin's specificity for branched alpha-mannans. A comparison of the dimeric banana lectin with other beta-prism I fold lectins, provides interesting insights into the variability in their quaternary structure.
DOI：
10.1046/j.1432-1327.2001.02148.x
发表时间：
2001-05-01
期刊：
EUROPEAN JOURNAL OF BIOCHEMISTRY
影响因子：
--
作者：
Mo, HQ;Winter, HC;Goldstein, IJ
通讯作者：
Goldstein, IJ