PDF(Pubmed)
Abstract：
BACKGROUND: We previously found the first examples of splicing of archaeal pre-mRNAs for homologs of the eukaryotic CBF5 protein (also known as dyskerin in humans) in Aeropyrum pernix, Sulfolobus solfataricus, S. tokodaii, and S. acidocaldarirus, and also showed that crenarchaeal species in orders Desulfurococcales and Sulfolobales, except for Hyperthermus butylicus, Pyrodictium occultum, Pyrolobus fumarii, and Ignicoccus islandicus, contain the (putative) cbf5 intron. However, the exact timing of the intron insertion was not determined and verification of the putative secondary loss of the intron in some lineages was not performed.
RESULTS: In the present study, we determined approximately two-thirds of the entire coding region of crenarchaeal Cbf5 sequences from 43 species. A phylogenetic analysis of our data and information from the available genome sequences suggested that the (putative) cbf5 intron existed in the common ancestor of the orders Desulfurococcales and Sulfolobales and that probably at least two independent lineages in the order Desulfurococcales lost the (putative) intron.
CONCLUSIONS: This finding is the first observation of a lineage-specific loss of a pre-mRNA intron in Archaea. As the insertion or deletion of introns in protein-coding genes in Archaea has not yet been seriously considered, our finding suggests the possible difficulty of accurately and completely predicting protein-coding genes in Archaea.
RESULTS: In the present study, we determined approximately two-thirds of the entire coding region of crenarchaeal Cbf5 sequences from 43 species. A phylogenetic analysis of our data and information from the available genome sequences suggested that the (putative) cbf5 intron existed in the common ancestor of the orders Desulfurococcales and Sulfolobales and that probably at least two independent lineages in the order Desulfurococcales lost the (putative) intron.
CONCLUSIONS: This finding is the first observation of a lineage-specific loss of a pre-mRNA intron in Archaea. As the insertion or deletion of introns in protein-coding genes in Archaea has not yet been seriously considered, our finding suggests the possible difficulty of accurately and completely predicting protein-coding genes in Archaea.
摘要：
背景：我们先前在Pernix中发现了真核CBF5蛋白（在人类中也称为dyskerin）同源物的古细菌pre-mRNA剪接的第一个实例，sulfolobussolfataricus,S、Tokodaii，和S.acidocaldarirus，还表明，在脱硫弧菌和硫磺属目中，除了丁基热热病，阴囊，福马里岛恶轮虫，和Ignicocusislandicus,含有（推定的）cbf5内含子。然而,内含子插入的确切时间尚未确定,也未对某些谱系中内含子的推定次要丢失进行验证.
结果：在本研究中，我们确定了来自43个物种的CrenarchaealCbf5序列的整个编码区的大约三分之二。对我们的数据和来自可用基因组序列的信息的系统发育分析表明，（假定的）cbf5内含子存在于脱硫球菌和Sulfolobales的共同祖先中，并且可能至少有两个独立的谱系在脱硫球菌中丢失了（假定的）内含子。
结论：这一发现是首次观察到古细菌中一个前mRNA内含子的谱系特异性丢失。由于古生菌蛋白质编码基因内含子的插入或缺失尚未得到认真考虑,我们的发现提示在古细菌中准确和完整地预测蛋白质编码基因可能存在困难.
结果：在本研究中，我们确定了来自43个物种的CrenarchaealCbf5序列的整个编码区的大约三分之二。对我们的数据和来自可用基因组序列的信息的系统发育分析表明，（假定的）cbf5内含子存在于脱硫球菌和Sulfolobales的共同祖先中，并且可能至少有两个独立的谱系在脱硫球菌中丢失了（假定的）内含子。
结论：这一发现是首次观察到古细菌中一个前mRNA内含子的谱系特异性丢失。由于古生菌蛋白质编码基因内含子的插入或缺失尚未得到认真考虑,我们的发现提示在古细菌中准确和完整地预测蛋白质编码基因可能存在困难.
