SEQUENCE AND REGULATION OF VITAMIN K BIOSYNTHESIS GENES

这次调查的主要目的是了解这一规定。 维生素K所涉及的基因和酶的表达 生物合成途径。维生素K是一种重要的脂溶维生素 是人类和动物的福祉所必需的。维生素K 应激性血栓原减少是一个重要的临床问题。 条件的数量。人体肠道的细菌区系 提供人体所需维生素K的50%-100%。 维生素K来源于莽草酸途径，它是由 异氨基甲酸酯和2-酮戊二酸。一直以来的中间体 确定的是2-succinyl-6-hydroxy-2，4-cyclohexadiene-1-carboxylate (SHCHC)，邻丁二酸苯甲酸酯(OSB)，OSB的CoA酯(OSB-CoA)， 2-二羟基-2-萘甲酸酯(DHNA)和去甲基菜籽酮(DMK)。 位于染色体48.5分钟的Mend、C、E和B基因有 已被克隆和测序。院士的MENA基因序列分析 正在进行中，我们将鉴定和克隆用于转化的基因 DMK-&gt；MK。要克服使用Small的困难 大量的酶和中间体，我们将使用操纵子和蛋白质 融合来研究调控，我们将把基因引入到 超量表达载体用于酶的高效生产、纯化和研究 该途径的中间体。

The principal aim of this investigation is to understand the regulation of expression of the genes and enzymes involved in the vitamin K biosynthetic pathway. Vitamin K is an important fat soluble vitamin that is required for the well being of humans and animals. Vitamin K responsive hypoprothrombia is an important clinical problem under a number of conditions. The bacterial flora of the human intestine contribute from 50-100% of the human vitamin K requirement. Vitamin K is derived from the "shikimate pathway" and it is formed from isochorismate and 2-ketoglutarate. The intermediates that have been identified are 2-succinyl-6-hydroxy-2,4-cyclohexadiene-1-carboxylate (SHCHC), o-succinylbenzoate (OSB), a CoA ester of OSB (OSB-CoA), 1,4- dihydroxy-2-naphthoate (DHNA), and desmethylmenaquinone (DMK). The menD, C, E, and B genes located at 48.5 min of the chromosome have been cloned and sequenced. The sequencing of the menA gene at 89 min is in progress and we will identify and clone the gene for the conversion of DMK---> MK. To overcome the difficulty of working with small quantities of enzymes and intermediates, we will use operon and protein fusions to study regulation and we will introduce the genes into overexpression vectors to overproduce, purify and study the enzymes and intermediates of the pathway.