The Increase in the Number of Subunits in Eukaryotic RNA Polymerase III Relative to RNA Polymerase II Is due to the Permanent Recruitment of General Transcription Factors
The Increase in the Number of Subunits in Eukaryotic RNA Polymerase III Relative to RNA Polymerase II Is due to the Permanent Recruitment of General Transcription Factors
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DOI：
10.1093/molbev/msp316
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发表时间：
2010-05-01
影响因子：
10.7
通讯作者：
Drouin, Guy
中科院分区：
文献类型：
--
作者：
Carter, Robert;Drouin, Guy
在进化过程中，RNA聚合酶亚基(RNAP)的数量从真细菌的5个增加到古生菌的12个。在至少有3个RNAP的真核生物中，亚基的数量已经从RNA聚合酶II(RNAPII)的12个扩大到RNA聚合酶I(RNAPI)的14个和RNA聚合酶III(RNAPIII)的17个。最近的研究表明，在RNAPI中发现的与RNAPII相关的另外两个亚基与RNAPII的二聚体转录因子TFIIF同源。在这里，我们通过证明五个RNAPIII特异性亚基中的四个也与RNAPII的转录因子同源来扩展这一发现。我们利用现有的证据来提出真核生物RNAPs的进化史，并认为RNAPs I和III中出现的亚基数量的增加是由于先前存在的转录因子的永久招募。
The number of subunits of RNA polymerases (RNAPs) increases during evolution from 5 in eubacteria to 12 in archaea. In eukaryotes, which have at least three RNAPs, the number of subunits has expanded from 12 in RNA polymerase II (RNAPII) to 14 in RNA polymerase I (RNAPI) and to 17 in RNA polymerase III (RNAPIII). It was recently demonstrated that the two additional subunits found in RNAPI relative to RNAPII are homologous to TFIIF, a dimeric general transcription factor of RNAPII. Here, we extend this finding by demonstrating that four of the five RNAPIII-specific subunits are also homologous to transcription factors of RNAPII. We use the available evidence to propose an evolutionary history of the eukaryotic RNAPs and argue that the increases in the number of subunits that occurred in RNAPs I and III are due to the permanent recruitment of preexisting transcription factors.