Evolutionary conservation of C-terminal domains of primary Sigma70-type transcription factors between plants and bacteria
Evolutionary conservation of C-terminal domains of primary Sigma70-type transcription factors between plants and bacteria
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DOI：
10.1074/jbc.275.13.9215
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发表时间：
2000-03-31
影响因子：
4.8
通讯作者：
Lerbs-Mache, S
中科院分区：
文献类型：
--
作者：
Hakimi, MA;Privat, I;Lerbs-Mache, S
最近从拟南芥中克隆了三个不同的编码植物质体sigma（70）型转录起始因子的cDNA，并进行了序列测定。我们通过异源转录系统的体外转录研究和大肠杆菌温敏rpoD突变体的互补分析，分析了这三个sigma因子的N端和C端功能的进化保守性。我们的研究结果表明，三种植物因子和它们的原核祖先的差异和相似之处。植物sigma因子的N-末端部分的功能与主sigma（70）因子off的N-末端部分的功能显著不同。另一方面，与原核生物相比，C端部分至少保留了两个特征：1）它们可以区分不同的启动子结构，2）其中一个能够完全互补于大肠杆菌。coli rpoD突变体，即大肠杆菌rpoD突变体。识别大肠杆菌所使用的所有必需的大肠杆菌启动子。大肠杆菌主σ（70）因子。这是第一次在体内的原核和植物质体转录机器之间的顺式和反式作用元件的强大的进化保守。
Three different cDNAs coding for putative plant plastid sigma(70)-type transcription initiation factors have recently been cloned and sequenced from Arabidopsis thaliana, We have analyzed the evolutionary conservation of function(s) of the N-terminal and C-terminal halves of these three sigma factors by in in vitro transcription studies using heterologous transcription systems and by complementation assays using Escherichia coli thermosensitive rpoD mutants. Our results indicate differences and similarities of the three plant factors and their prokaryotic ancestors. The functions of the N-terminal parts of the plant sigma factors are considerably different from the function of the N-terminal part of the principal sigma(70) factor off. coli, On the other hand, the C-terminal parts have kept at least two characteristics when compared with their prokaryotic ancestors: 1) they can distinguish between different promoter structures, and 2) one of them is capable of fully complementing E. coli rpoD mutants, i,e. recognizing all essential E, coli promoters that are used by the E. coli principal sigma(70) factor. This shows for the first time in vivo a strong evolutionary conservation of cis- and trans-acting elements between the prokaryotic and the plant plastid transcriptional machinery.