X-ray crystal structure of the human dimeric S-Lac lectin, L-14-II, in complex with lactose at 2.9-A resolution.
X-ray crystal structure of the human dimeric S-Lac lectin, L-14-II, in complex with lactose at 2.9-A resolution.
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DOI：
10.2210/pdb1hlc/pdb
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发表时间：
1994-04
期刊：
影响因子：
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通讯作者：
Y. Lobsanov;M. Gitt;H. Leffler;S. Barondes;J. Rini
中科院分区：
文献类型：
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作者：
Y. Lobsanov;M. Gitt;H. Leffler;S. Barondes;J. Rini
S-Lac凝集素是可溶性乳糖结合动物凝集素家族，其中一些凝集素通过特异性碳水化合物介导的识别参与调节细胞-细胞和细胞-基质相互作用。我们在这里报告的X-射线晶体结构的一个代表性的成员，这个家庭，人的二聚体S-紫胶凝集素，L-14-II，在复杂的乳糖，在2.9-A分辨率。双重对称二聚体由两个延伸的反平行β-折叠组成，它们以β-夹心基序缔合。值得注意的是，L-14-II单体不仅具有相同的拓扑结构，而且与豆科植物凝集素具有非常相似的β-折叠结构，这表明了保守的结构-功能关系。碳水化合物结合的L-14-II被发现涉及的蛋白质残基是非常高度保守的所有S-Lac凝集素。这些残基映射到一个单一的DNA外显子，这表明一个碳水化合物结合盒共同的所有S-Lac凝集素。
S-Lac lectins are a family of soluble lactose-binding animal lectins, some of which have been implicated in modulating cell-cell and cell-matrix interactions through specific carbohydrate-mediated recognition. We report here the x-ray crystal structure of a representative member of this family, the human dimeric S-Lac lectin, L-14-II, in complex with lactose, at 2.9-A resolution. The two-fold symmetric dimer is made up of two extended anti-parallel beta-sheets, which associate in a beta-sandwich motif. Remarkably, the L-14-II monomer shares not only the same topology, but a very similar beta-sheet structure with that of the leguminous plant lectins, suggesting a conserved structure-function relationship. Carbohydrate binding by L-14-II was found to involve protein residues that are very highly conserved among all S-Lac lectins. These residues map to a single DNA exon, suggesting a carbohydrate binding cassette common to all S-Lac lectins.