THE PENICILLIN-BINDING PROTEINS OF BACILLUS SUBTILIS

该项目的目的是检查和评估 青霉素结合蛋白（PBPs）的枯草芽孢杆菌在各种条件下 生理条件。 长期目标是将 这些蛋白质的活性与这些生物过程，如生长 细胞壁，在细胞分裂或孢子形成期间隔膜的形成， 以及前孢子发育过程中皮层的合成。 由于所有 假定这些事件易受青霉素抑制， 至少有一些PBPs的作用必须是必不可少的， 正常完成。 将作出重大努力来评估PBP的变化 因为有两个青霉素敏感的 在这一发展过程中的步骤，因为早期阶段的 孢子形成与营养细胞中发生事件非常相似 师. PBP波动的性质，它们的物理位置， 它们的时机和普遍性将受到审查。 以补充 在这些研究中，植物PBPs的地形分布在 细胞膜将通过比较来自 小细胞（主要是细胞末端）与杆状细胞（主要是 单元侧壁）。 此外，还对2个菌株的表型特征进行了分析。 现有的PBP缺陷突变体将被用来寻找一些生物学上的 可以归因于特定PBP缺陷的性质或功能。 这些PBP突变体和其他可能在我们提出的调查中发现的突变体， B的可用细胞形状和细胞分裂突变体。枯草杆菌将是 遗传分析的对象开始绘制PBP基因， 确定它们之间的联系，并将它们与特定的 表型特性 这里提出的各种方法 应该大大增加了我们对体内作用的稀疏知识， 这些PBPs。 这些信息将补充和扩展 我们主要从体外生物化学分析中获得的理解。 这些结果应该提供一些重要和有用的见解， 细胞分裂和孢子形成的机制，它们的调节， 青霉素的抑制作用。 在另一个层面上，关于 孢子形成最终可以使我们更好地操纵这一过程， 产生各种孢子形成特异性产物， 用于工业和医疗用途的酶、外毒素和抗生素。

The purpose of this project is to examine and evaluate the penicillin-binding proteins (PBPs) of Bacillus subtilis under a variety of physiological conditions. The long range goal is to correlate the activities of these proteins with such biological processes as growth of the cell wall, formation of the septum during cell division or sporulation, and synthesis of the cortex layer in the developing forespore. Since all these events are susceptible to inhibition by penicillin, it is assumed that the action of at least some of the PBPs must be essential for their normal completion. A major effort will be made to evaluate the PBP changes that occur during sporulation because there are 2 penicillin-sensitive steps in this developmental process and because the early stages of sporulation are very similar to events occuring in a vegetative cell division. The nature of the PBP fluctuations, their physical location, their timing, and their universality will be examined. As a complement to these studies, the topographical distribution of the vegetative PBPs within the cell membrane will be determined by a comparison of membranes from minicells (primarily cell ends) with those from rod-shaped cells (primarily cell sidewalls). Furthermore, a phenotypic characterization of the 2 existing PBP-deficient mutants will be done to look for some biological property or function that can be attributed to the specific PBP defect. These PBP mutants and others that may be found in our proposed survey of the available cell shape and cell division mutants of B. subtilis will be the subjects of genetic analysis to begin to map the PBP genes, to determine their linkage to one another, and to correlate them with specific phenotypic properties. The various approaches that are proposed here should significantly add to our sparse knowledge of the in vivo roles of these PBPs. This information will both complement and extend the understanding we have gained primarily from in vitro biochemical analyses. The results should provide some important and useful insights into the mechanisms of cell division and sporulation, their regulation, and their inhibition by penicillin. On another level, additional information about sporulation could ultimately enable us to manipulate the process better for the production of various sporulation-specific products such as proteolytic enzymes, exotoxins, and antibiotics for industrial and medical uses.