Occurrence of multiple, independent gene fusion events for the fifth and sixth enzymes of pyrimidine biosynthesis in different eukaryotic groups
Occurrence of multiple, independent gene fusion events for the fifth and sixth enzymes of pyrimidine biosynthesis in different eukaryotic groups
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DOI：
10.1016/j.gene.2007.02.009
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发表时间：
2007-06-01
期刊：
影响因子：
3.5
通讯作者：
Aoki, Takashi
中科院分区：
文献类型：
--
作者：
Makiuchi, Takashi;Nara, Takeshi;Aoki, Takashi
乳清酸磷酸核糖基转移酶（OPRT）和乳清酸核苷-5 '-单磷酸脱羧酶（OMPDC）是嘧啶从头合成途径中的第五和第六个酶，在大多数真核生物中，它们的基因融合为OPRT-OMPDC。另一方面，反向连接的OMPDC-OPRT融合体存在于锥虫中，锥虫与bodonids一起属于动质体超类群Euglenozoa。在这里，我们显示存在OMPDC-OPRT的bodonid，Bodo caudatus，而OPRT-OMPDC在眼虫，另一种眼虫属的眼虫。这些结果表明，OMPDC-OPRT融合事件发生在动质体的共同祖先中。基因组序列数据库搜索进一步揭示了在层藻和蓝藻中存在OMPDC-OPRT。OPRT和OMPDC的系统发育重建拒绝统计学的单系性的OPRT结构域的stratonile和动质体OMPDC-OPRT表明，这些基因融合不共享一个共同的进化起源，尽管相同的基因顺序。因此，OMPDC-OPRT融合很可能在这些真核生物组中独立出现。系统发育分析还表明，蓝藻OMPDC-OPRT通过横向转移。我们的结论是，基因融合事件发生的频率比以前认为的，横向基因转移作出了显着的贡献，在真核生物中的OPRT和OMPDC基因的重排结构的建立。(C)2007 Elsevier B. V.保留所有权利。
The genes encoding orotate phosphoribosyltransferase (OPRT) and orotidine-5 '-monophosphate decarboxylase (OMPDC), the fifth and sixth enzymes in the de novo pyrimidine biosynthetic pathway, are fused as OPRT-OMPDC in most eukaryotic groups. On the other hand, the inversely linked OMPDC-OPRT fusion is present in trypanosomatids, belonging to kinetoplastids together with bodonids in a supergroup, Euglenozoa. Here, we show the presence of OMPDC-OPRT in the bodonid, Bodo caudatus, while OPRT-OMPDC in Euglena gracilis, another euglenozoan species belonging to euglenoids. These results suggest that the OMPDC-OPRT fusion event occurred in a common ancestor of kinetoplastids. Genome sequence database searches further revealed the presence of OMPDC-OPRT in stramenopiles and cyanobacteria. Phylogenetic reconstruction of OPRT and OMPDC rejected statistically the monophyly of the OPRT domains of stramenopile and kinetoplastid OMPDC-OPRT demonstrating that these gene fusions do not share a common evolutionary origin, despite the identical gene order. Thus, the OMPDC-OPRT fusion is likely to have emerged independently in these eukaryotic groups. Phylogenetic analyses also suggested that cyanobacterial OMPDC-OPRT arose via lateral transfer. We conclude that gene fusion events occur more frequently than previously thought and that lateral gene transfer has made a marked contribution to establishment of the rearranged structure of OPRT and OMPDC genes in eukaryotes. (C) 2007 Elsevier B.V. All rights reserved.