一种新的阴道毛滴虫铁氧还蛋白基因(英文)  

A New (2Fe-2S) Ferredoxin Gene from Trichomonas vaginalis

作　　者：傅玉才[1] 徐虹[1] 章家新[1] 张可浩[1] 刘红[1] 林晖榕[1] 郑晓虹[1] 

机构地区：[1]汕头大学医学院寄生虫学教研室,汕头515041

出　　处：《热带医学杂志》2004年第4期352-356,381,共6页Journal of Tropical Medicine

基　　金：This work was supported by the Shantou Uni-versity Foundation for Researchand Devel-opment(No.L00013).

摘　　要：目的铁氧还蛋白系铁硫蛋白,在多种反应体系中起着传递电子的作用,也参与抗滴虫药物甲硝咪唑杀虫作用的激活。本研究旨在克隆和分析阴道毛滴虫铁氧还蛋白基因,以便进一步探讨其生理功能。方法构建阴道毛滴虫cDNA表达文库,分离cDNA进行克隆、测序及序列分析。结果在分离出的cDNA克隆中发现一个新的铁氧还蛋白基因。该基因读码框全长312bp,相应蛋白质序列具103个氨基酸;在该蛋白质前体的N端带有10个氨基酸残基的氢酶体靶片段(MLSQCSPLRF)。序列分析显示该铁氧还蛋白(TvFd2)与已报道的阴道毛滴虫铁氧还蛋白(TvFd)有高度同源性(69%);TvFd2与铁氧还蛋白(2Fe-2S)的两大亚类(氧化酶铁氧还蛋白和光合铁氧还蛋白)均具较低的同源性;可与(2Fe-2S)结合的4个半胱氨酸排列成典型的铁氧还蛋白保守序列(-C-X5-C-X2-C-Xn-C-)。结论分析表明TvFd2是一新的阴道毛滴虫铁氧还蛋白,其功能有待进一步研究。Objectives The ferredoxins are iron sulfur proteins, which function in electron transfer reactions in a variety of systems and participate in the activation of the antimicrobial agent metronidazole. The aim of this study is to clone and characterize ferredoxin genes of Trichomonas vaginalis. Methods A cDNA expression library was constructed with T. vaginalis total RNA. Hundreds of cDNA clones were isolated and sequenced. Sequence analysis was performed using BLAST programs, ClustalW program, etc. Results One of the cDNA clones, which has homology with T.vaginalis ferredoxin, was further analyzed. This cDNA clone has an open reading frame of 312 base pairs. The deduced precursor protein contains 103 amino acid residues with a hydrogenosome targeting sequence (MLSQCSPLRF) at the N terminal end. The primary sequence analysis revealed that this new ferredoxin (TvFd2) has a high homology (69%identity) to the previous reported T.vaginalis ferredoxin(TvFd). Interestingly, TvFd2 is homologous to both the two subclasses of (2Fe 2S) ferredoxins, the oxidase ferredoxins and the photosynthetic ferredoxins,but with low similarity. The conserved four cysteine residues, which are predicted to form the iron sulfur cluster,are arranged in a typical pattern of (2Fe 2S)ferredoxins( C X5 C X2 C Xn C ). Conclusion These data show that TvFd2 is a putative new (2Fe 2S) ferredoxin of T.vaginalis. Its biological function remains to be studied.

关 键 词：阴道毛滴虫 铁氧还蛋白 基因克隆 

分 类 号：R382.21[医药卫生—医学寄生虫学]