Selenium metabolism in <i>Drosophila</i> -: Characterization of the selenocysteine tRNA population

作     者：Zhou, X Park, SI Moustafa, ME Carlson, BA Crain, PF Diamond, AM Hatfield, DL Lee, BJ 

作者机构：Seoul Natl Univ Inst Mol Biol & Genet Genet Mol Lab Seoul 151742 South Korea NCI Sect Mol Biol Selenium Lab Basic Res NIH Bethesda MD 20892 USA Univ Utah Dept Med Chem Salt Lake City UT 84112 USA Univ Illinois Dept Human Nutr & Dietet Chicago IL 60612 USA 

出 版 物：《JOURNAL OF BIOLOGICAL CHEMISTRY》 (生物化学杂志)

年 卷 期：1999年第274卷第26期

页      面：18729-18734页

核心收录：

学科分类：0710[理学-生物学] 071010[理学-生物化学与分子生物学] 07[理学] 

基　　金：NCI NIH HHS [R01 CA81153] Funding Source: Medline NIGMS NIH HHS [R01 GM29812] Funding Source: Medline 

主　　题：细胞 培养的 染色体图 密码子 黑腹果蝇/遗传学 黑腹果蝇/代谢 电泳 聚丙烯酰氨凝胶 RNA 转移 氨基酸特异/代谢 硒/代谢 爪蟾属 动物 

摘      要：The selenocysteine (Sec) tRNA population in Drosophila melanogaster is aminoacylated with serine, forms selenocysteyl-tRNA, and decodes UGA. The K-m of Sec tRNA and serine tRNA for seryl-tRNA synthetase is 6.67 and 9.45 nM, respectively. Two major bands of Sec tRNA were resolved by gel electrophoresis, Both tRNAs were sequenced, and their primary structures were indistinguishable and colinear with that of the corresponding single copy gene. They are 90 nucleotides in length and contain three modified nucleosides, 5-methylcarboxymethyluridine, N-6-isopentenyladenosine, and pseudouridine, at positions 34, 37, and 55, respectively. Neither form contains 1-methyladenosine at position 58 or 5-methylcarboxymethyl-2 -O-methyluridine which are characteristically found in Sec tRNA of higher animals. We conclude that the primary structures of the two bands of Sec tRNA resolved by electrophoresis are indistinguishable by the techniques employed and that See tRNAs in Drosophila may exist in different conformational forms. The Sec tRNA gene maps to a single locus on chromosome 2 at position 47E or F, To our knowledge, Drosophila is the lowest eukaryote in which the Sec tRNA population has been characterized to date.