1月3日,国际著名杂志Plos One在线刊登了一篇文章“细菌基因组调节子的染色体排布”( Genomic Arrangement of Regulons in Bacterial Genomes),文章的通讯作者是来自吉林大学计算机学院的客座教授徐鹰,在文章中,作者用计算机技术来阐述了细菌调节子的排布规则。
调节子是细菌细胞基本的效应系统调节子,在研究细菌的领域内,调节子是一个最基本的概念,细菌的调节子是一组操纵子,是通过相同的调节网络来进行的转录共调节,调节子主要包括trans调节器(一般的转录调控因子)和位于操纵子启动子前的cis调节结合原件;一个调节子包含了由一种转录因子调节的很多操纵子。
1964年,科学家提出了regulon(调节子)这个概念,随后研究者们在大肠杆菌中K12发现了173种调节子,在枯草芽孢杆菌中发现了更多的调节子;通俗来讲,调节子被分为两种类型:局部调节子和全局调节子,前者指的是调节子含有为数不多的操纵子成分,而后者指的是含有相对多的操纵子成分,尽管我们已经学到了已知的调节子的部分功能性,可是对于调节子是如何在细菌基因组中发挥作用的却知之甚少。
文章的作者徐鹰教授是国际著名计算生物学家,美国佐治亚大学生物化学与分子生物学系教授,生物信息学研究所所长,兼职吉林大学客座教授,在这篇文章中,作者首次用计算机科学来阐释细菌基因组中调节子的组织架构法则,他们选用的是大肠杆菌K12和枯草芽孢杆菌str.168来进行研究,最终作者的结果表明,每一个调节子中的操纵子趋向于形成一段绕着染色体紧密在一起的基因簇,转录因子比转录靶点在进化上更有严格的规定,基因组中所有调节子的操纵子组分的全局排布趋向于使功能得到最大发挥。(生物谷Bioon.com)
(T.Shen编译 如有问题请及时指正)
doi:10.1371/journal.pone.0029496
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Genomic Arrangement of Regulons in Bacterial Genomes
Han Zhang1,2#, Yanbin Yin1,3#, Victor Olman1, Ying Xu1,3,4*
Regulons, as groups of transcriptionally co-regulated operons, are the basic units of cellular response systems in bacterial cells. While the concept has been long and widely used in bacterial studies since it was first proposed in 1964, very little is known about how its component operons are arranged in a bacterial genome. We present a computational study to elucidate of the organizational principles of regulons in a bacterial genome, based on the experimentally validated regulons of E. coli and B. subtilis. Our results indicate that (1) genomic locations of transcriptional factors (TFs) are under stronger evolutionary constraints than those of the operons they regulate so changing a TF's genomic location will have larger impact to the bacterium than changing the genomic position of any of its target operons; (2) operons of regulons are generally not uniformly distributed in the genome but tend to form a few closely located clusters, which generally consist of genes working in the same metabolic pathways; and (3) the global arrangement of the component operons of all the regulons in a genome tends to minimize a simple scoring function, indicating that the global arrangement of regulons follows simple organizational principles.