A prokaryotic gene cluster involved in synthesis of lysine through the amino adipate pathway: A key to the evolution of amino acid biosynthesis
A prokaryotic gene cluster involved in synthesis of lysine through the amino adipate pathway: A key to the evolution of amino acid biosynthesis
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DOI：
10.1101/gr.9.12.1175
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发表时间：
1999-12-01
期刊：
影响因子：
7
通讯作者：
Yamane, H
中科院分区：
文献类型：
--
作者：
Nishida, H;Nishiyama, M;Yamane, H
在以前的研究中，我们确定了一个极端嗜热菌Thermus thermophilus的基因簇的核苷酸序列，该基因簇包含lys 20，hacA（lys 4A），hacB（lys 4 B），orfE，orfF，rimK，argC和argB。在这项研究中，我们的特点是在集群中的每个基因的作用，基因中断和研究营养缺陷型的破坏者。除了orfE破坏外，所有破坏物均显示赖氨酸营养缺陷型表型。这是令人惊讶的，因为这个簇由基于其名称编码不相关蛋白质的基因组成，这些蛋白质已通过同源性分析暂时命名。虽然新发现的途径含有α-氨基己二酸作为赖氨酸生物合成的中间体，但该途径与真核生物的途径不同。通过对每个基因产物的微卫星遗传学分析，我们发现T. Thermophilus均存在于一种极端嗜热厌氧古菌Pyrococcus horikoshii中，并以类似于T.嗜热菌此外，该基因簇部分类似于本发明的亮氨酸和精氨酸生物合成途径。该赖氨酸生物合成簇被认为是赖氨酸生物合成的起源之一，因此可能成为氨基酸生物合成进化的关键。
In previous studies we determined the nucleotide sequence of the gene cluster containing lys20, hacA (lys4A), hacB (lys4B), orfE, orfF, rimK, argC, and argB of Thermus thermophilus, an extremely thermophilic bacterium. In this study, we characterized the role of each gene in the cluster by gene disruption and examined auxotrophy in the disruptants. All disruptants except for the orfE disruption showed a lysine auxotrophic phenotype. This was surprising because this cluster consists of genes coding for unrelated proteins based on their names, which had been tentatively designated by homology analysis. Although the newly found pathway contains alpha-aminoadipic acid as a lysine biosynthetic intermediate, this pathway is not the same as the eukaryotic one. When each of the gene products was phylogenetically analyzed, we Found that genes evolutionarily-related to the lysine biosynthetic genes in T. thermophilus were all present in a hyperthermophilic and anaerobic archaeon, Pyrococcus horikoshii, and Formed a gene cluster in a manner similar to that in T. thermophilus. Furthermore, this gene cluster was analogous in part to the present leucine and arginine biosyntheses pathways. This lysine biosynthesis cluster is assumed to be one of the origins of lysine biosynthesis and could therefore become a key to the evolution of amino acid biosynthesis.