GENETIC ANALYSIS--ADHESION OF S SANGUIS TO S PELLICLE

本提案的总体目标是描述 副血链球菌FW213菌毛粘附素（FimA） 分子水平。 这种蛋白质，在整个基因组中高度保守， 血链球菌，已被证明是一种粘附素的成员， 四个基因组中至少有两个是 随后致病物种的增加。 数据来自几个 实验室强烈表明，生态演替发生在 牙菌斑的形成和发展， (SHA)似乎由几种不同的粘附素介导。 人们对链球菌的表达控制知之甚少， 粘附素或链球菌粘附素呈递的细胞途径。 我们的实验室最近发现了一种ATP结合的膜转运 与FimA相关的系统。 我们开发了一种有效的方法， 在S. parasanguis， 极大地促进了这种细菌的属分析。 与这些 工具，我们的实验室是独特的定位，以表征域 FimA参与粘附到唾液膜，并表征 其在细胞表面的表达和呈递。具体地说， 我们建议： 1. 鉴定fim基因座中的其他基因及其启动子。 2. 表征fim基因座编码的蛋白质的表达。 3. 表征FimA的活性结合结构域。 4. 通过互补， 突变的非粘附突变体的S.副囊 S粘附的分子和遗传特征。副血 牙齿表面现在是可能的，与工具开发，在这方面， 实验室 这项研究将有助于细菌领域 口腔环境中的粘附力以及对 链球菌的遗传学。 FIMA样链球菌的作用 作为双功能粘附素的蛋白质参与起始和 牙菌斑的多属积累需要进一步研究。 我们的工作还将探讨可能的功能和进化 基材粘合和输送与粘合剂之间的关系 与基质结合。 研究产生的治疗试剂， 因为目前的人可以在控制牙科方面发挥重要作用， 斑块发展和随后的疾病过程。

The overall goal of this proposal to characterize expression of the fimbrial adhesin (FimA) of Streptococcus parasanguis FW213 at the molecular level. This protein, which is highly conserved throughout the sanguis streptococci, has been shown to be an adhesin in members of at least two of the four genetic groups of sanguis a substrate for subsequent accretion of pathogenic species. Data from several laboratories strongly suggest that ecological succession takes place in the formation and development of dental plaque, and that the sanguis (SHA) appears to be mediated by several distinct adhesins. Little is understood of the control of expression of streptococcal adhesins or the cellular pathway of streptococcal adhesin presentation. Our laboratory has recently identified an ATP-binding membrane transport system associated with FimA. We have developed an efficient method for site-specific allelic replacement mutagenesis in S. parasanguis, which greatly facilitates generic analysis of this bacterium. With these tools, our laboratory is uniquely positioned to characterize the domains of FimA involved in adhesion to the salivary pellicle and to characterize its expression and presentation on the surface of the cell. Specifically, we propose: 1. To identify other genes in the fim locus and identify its promoter. 2. To characterize the expression of proteins encoded by the fim locus. 3. To characterize the active binding domain(s) of FimA. 4. To identify additional adhesion-related genes by complementing mutations in nonadherent mutants of S. parasanguls. Molecular and genetic characterization of the adhesion of S. parasanguis to dental surfaces is now possible, with the tools developed in this laboratory. This research will contribute to the field of bacterial adhesion in the oral environment as well as to the basic understanding of the genetics of streptococci. The role of FimA-like streptococcal proteins as bifunctional adhesins involved in both initiation and multigeneric accumulation of dental plaque needs to be further studied. Our work will also explore the possible functional and evolutionary relationship between substrate binding and transport, and adhesive binding to a substrate. Therapeutic reagents resulting from studies such as the present one could have an important role in controlling dental plaque development and the subsequent disease processes.