Homologues of bacterial TnpB_IS605 are widespread in diverse eukaryotic transposable elements
Homologues of bacterial TnpB_IS605 are widespread in diverse eukaryotic transposable elements
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DOI：
10.1186/1759-8753-4-12
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发表时间：
2013-04-01
期刊：
影响因子：
4.9
通讯作者：
Jurka, Jerzy
中科院分区：
文献类型：
--
作者：
Bao, Weidong;Jurka, Jerzy
背景：IS200/IS605和IS607家族的细菌插入序列通常编码一个转座酶(TnpA)和一个未知功能的蛋白质TnpB。结果：我们报道了两组TnpB样蛋白(Fanzor1和Fanzor2)，它们广泛存在于各种真核生物转座元件(TES)和感染真核生物的大型双链DNA(DsDNA)病毒中。Fanzor和TnpB蛋白在其C-末端半区有相同的保守氨基酸序列：D-X(125,275)-[TS]-[TS]-X-X-[C4锌指]-X(5，50)-RD，但在N-末端有很大的变异。Fanzor1蛋白经常被来自不同超家族的DNA转座子捕获，包括Helitron，Mariner，IS4-like，Sola和MuDR。相反，Fanzor2蛋白只出现在一些IS607型元件中。我们还分析了来自氦电子超家族的一个新的氦2族，它包含两端具有发夹结构的元件。莱茵衣藻基因组中的非自主Helitron2元件(Cre-1、Cre-2、Cre-3)两侧存在长度可变的靶点重复序列(TSD)。结论：TnpB/Fanzor蛋白的系统发育和分布表明它们可能通过病毒在真核生物中传播。我们推测TnpB/Fanzor蛋白可能作为甲基转移酶。
Background: Bacterial insertion sequences (IS) of IS200/IS605 and IS607 family often encode a transposase (TnpA) and a protein of unknown function, TnpB.Results: Here we report two groups of TnpB-like proteins (Fanzor1 and Fanzor2) that are widespread in diverse eukaryotic transposable elements (TEs), and in large double-stranded DNA (dsDNA) viruses infecting eukaryotes. Fanzor and TnpB proteins share the same conserved amino acid motif in their C-terminal half regions: D-X(125, 275)-[TS]-[TS]-X-X-[C4 zinc finger]-X(5,50)-RD, but are highly variable in their N-terminal regions. Fanzor1 proteins are frequently captured by DNA transposons from different superfamilies including Helitron, Mariner, IS4-like, Sola and MuDr. In contrast, Fanzor2 proteins appear only in some IS607-type elements. We also analyze a new Helitron2 group from the Helitron superfamily, which contains elements with hairpin structures on both ends. Non-autonomous Helitron2 elements (CRe-1, 2, 3) in the genome of green alga Chlamydomonas reinhardtii are flanked by target site duplications (TSDs) of variable length (approximately 7 to 19 bp).Conclusions: The phylogeny and distribution of the TnpB/Fanzor proteins indicate that they may be disseminated among eukaryotic species by viruses. We hypothesize that TnpB/Fanzor proteins may act as methyltransferases.