Selenocysteine Derivatives for Chemoselective Ligations
Selenocysteine Derivatives for Chemoselective Ligations
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DOI：
10.1002/1439-7633(20020802)3:8
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发表时间：
2002-08
期刊：
影响因子：
3.2
通讯作者：
Mathew D. Gieselman;Yantao Zhu;Hao Zhou;Danica P. Galonić;W. A. van der Donk
中科院分区：
文献类型：
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作者：
Mathew D. Gieselman;Yantao Zhu;Hao Zhou;Danica P. Galonić;W. A. van der Donk
硒代半胱氨酸（Sec或U）通常被称为第21种天然氨基酸，因为它存在于古细菌，真细菌和真核生物中的许多天然酶中。Sec是互补插入到这些蛋白质，并有自己的tRNA识别蛋白石终止密码子UGA。顺式（分子内）元件和反式（分子间）作用因子都有助于解码UGA以进行Sec插入，而不是中止翻译。在细菌中，紧邻UGA密码子下游的mRNA中的茎环结构（硒代半胱氨酸插入序列，SECIS）被专门的硒代半胱氨酸延伸因子识别（SelB，图1A）。然后将SelB、Sec ± tRNA、三磷酸鸟苷（GTP）和SECIS的四元复合物导向核糖体的A位点，用于与UGA密码子相对的Sec掺入。
Selenocysteine (Sec or U) is often referred to as the 21st natural amino acid because it is found in a number of naturally occurring enzymes in archaea, eubacteria, and eukarya. Sec is inserted cotranslationally into these proteins and has its own tRNA that recognizes the opal stop codon UGA. Both cis (intramolecular) elements and trans (intermolecular) acting factors are instrumental in decoding UGA for Sec insertion rather than aborting translation. In bacteria, a stem-loop structure in the mRNA immediately downstream of the UGA codon (the selenocysteine insertion sequence, SECIS) is recognized by a specialized selenocysteine elongation factor (SelB, Figure 1A). The quaternary complex of SelB, Sec ± tRNA, guanosine triphosphate (GTP), and the SECIS is then directed to the A site of the ribosome for Sec incorporation opposite the UGA codon.