Sequences homologous to yeast mitochondrial and bacteriophage T3 and T7 RNA polymerases are widespread throughout the eukaryotic lineage
Sequences homologous to yeast mitochondrial and bacteriophage T3 and T7 RNA polymerases are widespread throughout the eukaryotic lineage
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DOI：
10.1093/nar/24.4.648
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发表时间：
1996-02-15
影响因子：
14.9
通讯作者：
Gray, MW
中科院分区：
文献类型：
--
作者：
Cermakian, N;Ikeda, TM;Gray, MW
虽然线粒体和叶绿体被认为是类似真细菌的内共生生物的后代，但酵母的线粒体RNA聚合酶是一种核编码的单亚基酶，与噬菌体T3和T7 RNA聚合酶同源，而不是叶绿体DNA中编码的多组分真细菌型α (2) β β β酶。我们使用聚合酶链反应（PCR）方法来扩增噬菌体T3/T7样RNA聚合酶基因的内部部分，使用这种策略，我们从系统发育广泛的多细胞和单细胞真核生物中恢复了与酵母线粒体和噬菌体T3/T7 RNA聚合酶同源的序列，这些生物显示出线粒体基因组组织和表达的不同模式。在某些情况下，我们可以推断出pcr扩增的序列，其中一些包含小内含子，定位在核DNA中。我们推断，这里报道的T3/ t7样RNA聚合酶序列可能来自编码线粒体RNA聚合酶的基因，它们发生在生物体中。这表明噬菌体T3/ t7样RNA聚合酶在该细胞器进化的早期阶段被招募参与线粒体的转录。
Although mitochondria and chloroplasts are considered to be descendants of eubacteria-like endosymbionts, the mitochondrial RNA polymerase of yeast is a nucleus-encoded, single-subunit enzyme homologous to bacteriophage T3 and T7 RNA polymerases, rather than a multi-component, eubacterial-type alpha(2) beta beta' enzyme, as encoded in chloroplast DNA, To broaden our knowledge of the mitochondrial transcriptional apparatus, we have used a polymerase chain reaction (PCR) approach designed to amplify an internal portion of phage T3/T7-like RNA polymerase genes, Using this strategy, we have recovered sequences homologous to yeast mitochondrial and phage T3/T7 RNA polymerases from a phylogenetically broad range of multicellular and unicellular eukaryotes, These organisms display diverse patterns of mitochondrial genome organization and expression, and include species that separated from the main eukaryotic line early in the evolution of this lineage, In certain cases, we can deduce that PCR-amplified sequences, some of which contain small introns, are localized in nuclear DNA, We infer that the T3/T7-like RNA polymerase sequences reported here are likely derived from genes encoding the mitochondrial RNA polymerase in the organisms in which they occur, suggesting that a phage T3/T7-like RNA polymerase was recruited to act in transcription in the mitochondrion at an early stage in the evolution of this organelle.