Rab-subfamily-specific regions of Ypt7p are structurally different from other RabGTPases
Rab-subfamily-specific regions of Ypt7p are structurally different from other RabGTPases
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DOI：
10.1016/s0969-2126(02)00737-2
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发表时间：
2002-04-01
期刊：
影响因子：
5.7
通讯作者：
Scheldig, AJ
中科院分区：
文献类型：
--
作者：
Constantinescu, AT;Rak, A;Scheldig, AJ
来自酿酒酵母的 GTP 酶 Ypt7p 参与晚期内体到液泡的转运和同型液泡融合。我们展示了 Ypt7p 的 GDP 和 GppNHp 结合构象的晶体结构，分辨率分别为 1.35 和 1.6 埃。尽管整体结构与其他 Ypt/Rab 蛋白相似，但 Ypt7p 显示出微小但显着的差异。 Ypt7p 特异性残基 Tyr33 和 Tyr37 引起 RabSF2 区域主链轨迹的差异，并形成特征性表面表位，Ypt7p(.)GppNHp 不显示 Ras 超家族特征的螺旋 α2，而是具有延伸环 L4/L5。由于插入环 L3 和 L7，相邻的 RabSF1 和 RabSF4 区域的构象与其他 Ypt/Rab 蛋白的构象不同。
The GTPase Ypt7p from S. cerevisiae is involved in late endosome-to-vacuole transport and homotypic vacuole fusion. We present crystal structures of the GDP- and GppNHp-bound conformation of Ypt7p solved at 1.35 and 1.6 Angstrom resolution, respectively. Despite the similarity of the overall structure to other Ypt/Rab proteins, Ypt7p displays small but significant differences. The Ypt7p-specific residues Tyr33 and Tyr37 cause a difference in the main chain trace of the RabSF2 region and form a characteristic surface epitope, Ypt7p(.)GppNHp does not display the helix alpha2, characteristic of the Ras-superfamily, but instead possess an extended loop L4/L5. Due to insertions in loops L3 and L7, the neighboring RabSF1 and RabSF4 regions are different in their conformations to those of other Ypt/Rab proteins.