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.
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.