NUCLEOTIDE SEQUENCE AND CONTROL OF THE GLCDH OPERON

枯草芽孢杆菌在分化（孢子形成）时， 遭遇营养匮乏 许多新的蛋白质只有在 在孢子形成期间。 这种细菌的控制机制 这些发育调节基因的表达是未知的。 我们 目前正在研究控制一种孢子形成的机制 特异性基因，葡萄糖脱氢酶基因（GDH）。 这个基因和一个 在GDH之前的未表征的基因包含表达的操纵子 只有在孢子形成期间。 核苷酸序列和核糖体结合 地点已经确定。 启动子位于0.5 kb PvuI内， 区域，并已缩小到介于PvuI和PvuI站点之间。 没有 该片段中的核苷酸序列与任何已知的启动子 B序列。枯草杆菌RNA聚合酶。 DNA片段含有 将GDH操纵子的推定启动子序列插入到 质粒携带的启动子少的基因，以确定哪些序列是 是控制GDH孢子形成所必需的。 比较了B. 枯草芽孢杆菌DNA序列和B.巨大菌的氨基酸序列显示了 在gdh的进化过程中发生了多少和什么类型的突变。

Bacillus subtilis undergoes differentiation (sporulation) when it encounters nutrient deprivation. Many new proteins are synthesized only during sporulation. The mechanisms by which this bacterium controls the expression of these developmentally regulated genes are not known. We are currently investigating the mechanism(s) controlling one sporulation specific gene, the glucose dehydrogenase gene (gdh). This gene and an uncharacterized gene that precedes gdh comprise an operon that is expressed only during sporulation. The nucleotide sequence and ribosome binding sites have been determined. The promoter is located within a 0.5 kb PvuI region and has been narrowed to be between AluI and PvuI sites. No nucleotide sequence in this fragment matches any of the known promoter sequences of the B. subtilis RNA polymerases. DNA fragments that contain the putative promoter sequence of the gdh operon were inserted in front of plasmid-borne promoter-less genes to determine which sequences are necessary for sporulation control of gdh. A comparison between the B. subtilis DNA sequence and the B. megaterium amino acid sequence showed how many and what type of mutations occurred during the evolution of gdh.