SEQUENCE AND REGULATION OF VITAMIN K BIOSYNTHESIS GENES

这项调查的主要目的是深入了解 细菌维生素K生物合成的分子调控 结构和组织的检查和解剖 维生素K生物合成基因。维生素K是一种重要的脂肪 在人类和动物中发挥重要作用的可溶性维生素 健康。它的缺陷导致了几个重要的临床 低凝血酶原血症等病理改变。在健康的个体中 维生素K的大部分需求是由细菌满足的 肠道菌群生物合成。 维生素K-萘醌核的途径是合理的 以及参与合成各种基因的各种 酶已经被定位和克隆。维生素的合成 依赖于芳香氨基酸途径，并利用 异氨基甲酸酯和2-酮戊二酸为起始反应物。这个 经鉴定的中间体为2-琥珀酸基-6-羟基-2，4- 1-环己二烯-1-羧酸酯(SHCHC)，邻丁二酸苯甲酸酯(OSB) OSB酯(OSB-CoA)、1，4-二羟基-2-萘酸酯(DHNA)和 脱甲基甲喹酮(DMK)。 MENA基因位于88min，而menBCDE基因位于 48.5min的大肠杆菌连锁图谱。MAN集群已被克隆 将其克隆入pBR322中，测定其DNA序列。这 调查将确定其余人员的顺序 对基因进行分类并启动对这些基因调控的研究 使用Lacz融合。

The principal aim of this investigation is to gain insight into the regulation of bacterial vitamin K biosynthesis by the molecular examination and dissection of the structure and organization of vitamin K biosynthetic genes. Vitamin K is an important fat soluble vitamin which plays a significant role in human and animal health. Its deficiency leads to several significant clinical pathologies such as hypoprothrombinemia. In healthy individuals the bulk of the vitamin K requirement is met by bacterial biosynthesis of intestinal flora. The pathway for the vitamin k napthoquinone nucleus is reasonably understood, and the genes involved in the synthesis of the various enzymes have been mapped and cloned. The synthesis of the vitamin is dependent upon the aromatic amino acid pathway and utilizes isochorismate and 2-ketoglutarate as initial reactants. The identified intermediates are 2-succinyl-6-hydroxy-2,4- cyclohexadiene-1-carboxylate (SHCHC), o-succinylbenzoate (OSB) ester of OSB (OSB-CoA), 1,4-dihydroxy-2-naphthoate (DHNA) and desmethylmenaquinone (DMK). The menA gene is located at 88 min and the menBCDE gene cluster at 48.5 min of E. coli linkage map. The men cluster has been cloned into pBR322 and the DNA sequence of menD determined. This investigation will determine the sequence of the remaining men cluster genes and initiate studies of the regulation of these genes using lacZ fusions.