The GC-rich transposon Bytmar1 from the deep-sea hydrothermal crab, Bythograea thermydron, may encode three transposase isoforms from a single ORF
The GC-rich transposon Bytmar1 from the deep-sea hydrothermal crab, Bythograea thermydron, may encode three transposase isoforms from a single ORF
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DOI：
10.1007/s00239-004-2665-0
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发表时间：
2004-12-01
影响因子：
3.9
通讯作者：
Laulier, M
中科院分区：
文献类型：
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作者：
Halaimia-Toumi, N;Casse, N;Laulier, M
水手样元件（Mariner-like elements，MLEs）是一类具有高度保守序列特性的II类转座子，广泛存在于生活在大陆环境中的动物基因组中。我们在这里描述的第一个全长MLE中发现的海洋甲壳类物种的基因组中，深海热液蟹Bythograea thermydron（甲壳纲），命名为Bytmar 1。将其序列特征与大陆物种基因组中所含的MLE序列特征进行比较，揭示了几个独特的特征。首先，Bytinar 1元件包含一个ORF，其可以编码长度为349、379和398个氨基酸（aa）的三种转座酶异构体。这两个最大的蛋白质是由于分别在349-aa基数MLE转座酶的N-末端存在30-aa和49-aa标记。它们的GC含量也明显高于大陆MLE中的含量。该特征主要是由于转座酶ORF中的密码子使用，并直接干扰Bytmar 1核酸序列的曲率倾向。这种升高的GC含量可能干扰Bytmar 1形成切除复合物的能力，并因此干扰其转座效率。最后，这些特点的起源和它们可能的后果对转座效率进行了讨论。
Mariner-like elements (MLEs) are classII transposons with highly conserved sequence properties and are widespread in the genome of animal species living in continental environments. We describe here the first full-length MLE found in the genome of a marine crustacean species, the deep-sea hydrothermal crab Bythograea thermydron (Crustacea), named Bytmar1. A comparison of its sequence features with those of the MLEs contained in the genomes of continental species reveals several distinctive characteristics. First, Bytinar1 elements contains an ORF that may encode three transposase isoforms 349, 379, and 398 amino acids (aa) in long. The two biggest proteins are due to the presence of a 30- and 49-aa flag, respectively, at the N-terminal end of the 349-aa cardinal MLE transposase. Their GC contents are also significantly higher than those found in continental MLEs. This feature is mainly due to codon usage in the transposase ORF and directly interferes with the curvature propensities of the Bytmar1 nucleic acid sequence. Such an elevated GC content may interfere with the ability of Bytmar 1 to form an excision complex and, in consequence, with its efficiency to transpose. Finally, the origin of these characteristics and their possible consequences on transposition efficiency are discussed.