SEQUENCE AND REGULATION OF VITAMIN K BIOSYNTHESIS GENES

本次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 检查和解剖的结构和组织 维生素K生物合成基因 维生素K是重要的脂肪 可溶性维生素在人类和动物中起着重要作用 健康 它的缺陷导致几个重要的临床 病理学如低凝血酶原血症。 在健康个体中 大部分维生素K的需求是由细菌 肠道植物群的生物合成。 维生素k萘醌核的途径是合理的 了解，以及参与各种合成的基因 酶已经被定位和克隆。 维生素的合成 依赖于芳香族氨基酸途径， 异分支酸和2-酮戊二酸作为初始反应物。 的 已鉴定的中间体是2-琥珀酰基-6-羟基-2，4-二氢-1H-吡喃-2-酮， 环己二烯-1-羧酸酯（SHCHC）、邻琥珀酰苯甲酸酯（OSB） OSB的酯（OSB-CoA）、1，4-二羟基-2-萘甲酸酯（DHNA）和 去甲基甲萘醌（DMK）。 menA基因位于88 min处，menBCDE基因簇位于 48.5 min的E. coli连锁图谱。 男性集群已被克隆 转化到pBR 322中，并测定了menD的DNA序列。 这 调查将确定其余人的顺序 聚类基因，并启动对这些基因的调节的研究 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.