Engineered Functional Recovery of Microbial Rhodopsin without Retinal-Binding Lysine.
Engineered Functional Recovery of Microbial Rhodopsin without Retinal-Binding Lysine.
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不含视网膜结合赖氨酸的微生物视紫红质的工程功能恢复。
DOI：
10.1111/php.13114
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发表时间：
2019
期刊：
影响因子：
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通讯作者：
Hideki Kandori
中科院分区：
文献类型：
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作者：
Yumeka Yamauchi;Masae Konno;Daichi Yamada;Kei Yura;Keiichi Inoue;Oded Beja;Hideki Kandori
视紫红质的定义是视网膜结合膜蛋白，在第7跨膜螺旋上的赖氨酸处具有席夫碱键。然而，在约5500种已知的微生物视紫红质中，约600种微生物视紫红质在相应的位置（Rh-noK）缺乏结合视网膜的赖氨酸，这表明Rh-noK在没有发色团的情况下具有每种功能作用。在这里，我们报告了Rh-noK的成功功能恢复。在大肠杆菌中异源表达了两种来自细菌的Rh-noK，其不显示颜色。当引入视网膜结合赖氨酸时，其中一个获得了可见的颜色。席夫碱对映体的额外突变进一步获得质子泵活性。成功的工程功能恢复，如可见颜色和质子泵活性，表明Rh-noK蛋白形成了微生物视紫红质的特征结构。
Definition of rhodopsin is the retinal‐binding membrane protein with the Schiff base linkage at a lysine on the 7thtransmembrane helix. However, ~ 600 microbial rhodopsins lack retinal‐binding lysine at the corresponding position (Rh‐noK) among ~ 5500 known microbial rhodopsins, suggesting that Rh‐noK has each functional role without chromophore. Here, we report successful functional recovery of Rh‐noK. Two Rh‐noKs from bacteria were heterologously expressed inEscherichia coli, which exhibited no color. When retinal‐binding lysine was introduced, one of them gained visible color. Additional mutation of the Schiff base counterion further gained proton‐pumping activity. Successful engineered functional recovery such as visible color and proton‐pump activity suggests that the Rh‐noK protein forms a characteristic structure of microbial rhodopsins.