ROLE OF SURFACE MOLECULES IN THE METABOLISM AND ECOLOGY OF ORAL BACTERIA

表面分子在口腔细菌代谢和生态中的作用

• 批准号: 3854214
• 负责人: J LONDON
• 金额: --
• 依托单位: NATIONAL INSTITUTE OF DENTAL & CRANIOFACIAL RESEARCH
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/3854214
• 关键词: DNA replication; Streptococcus infection; Streptococcus sanguis; adhesin; aminosugar; bacterial proteins; binding proteins; carbohydrate metabolism; carbohydrates; cell adhesion; cell adhesion molecules; dental plaque; enzyme biosynthesis; fibronectins; laminin; membrane activity; microorganism metabolism; nucleic acid probes; oral bacteria; pilus; protein purification; protein sequence; proteolysis

The DNA sequence of the relatively large gene encoding the streptococcal- specific Prevotella loescheii adhesin has been completed. Sequence data indicates that the mature adhesin is larger than estimated, 88kD rather than 75kD. The gene, itself, is composed of 2.3kb. A 28 nucleotide base run following the twenty eight codon represents the start of a "ribosomal hop" which results in a frameshift. The 28 nucleotide sequence starts and ends with an ochre terminator (UAA) and contains two "slippery" runs of 4 adenines each within the run. A stem loop terminator follows the 28 nucleotide run. Thus far, P. loescheii appears to be only the second bacterium in which short chromosomal sequences within genes are not read. P. loescheii synthesizes at least three extracellular proteases which can be differentiated by ionic charge. At least one of these is capable of degrading the streptococcal-specific adhesin. These enzymes can be separated chromatographically and are currently being purified. The protease may provide the bacterium with a release mechanism from coaggregates or plaque. Enzymes responsible for the transport and metabolism of xylitol ribitol have been purified for the purpose of determining the N-terminal amino acid sequence. Once the sequences are known, DNA probes will be synthesized by backtranslation for the purpose of cloning the genes encoding enzyme IIIxtl, xylitol-5-P dehydrogenase and ribitol-5-P dehydrogenase.

编码链球菌的较大基因的DNA序列- 特异普雷沃特拉粘附素已经完成。序列数据 表明成熟的粘附素比估计的要大，88kD。 大于75kD。该基因本身由2.3kb组成。一个28个核苷酸的碱基 跟随28个密码子的Run代表了“核糖体”的开始 这会导致移码。28个核苷酸序列开始并 以一个赭色终止符(UAA)结束，包含两个4的“滑行” 每一种腺苷都在奔跑中。28后面有一个主干环终止符 核苷酸运行。到目前为止，P.Loescheii似乎只是第二个 基因内的短染色体序列没有被读取的细菌。 洛氏假单胞菌至少能合成三种胞外蛋白水解酶 通过离子电荷来区分。其中至少有一个能够 降解链球菌特有的粘附素。这些酶可以是 经层析分离，目前正在进行纯化。这个 蛋白水解酶可以为细菌提供一种从 共聚体或斑块。 木糖醇核糖醇转运和代谢的酶 已被提纯，用于确定N-末端氨基 酸序列。一旦知道了序列，DNA探针就会 通过反向翻译合成的，目的是克隆基因 编码酶IIIxtl、木糖醇-5-P脱氢酶和核糖醇-5-P 脱氢酶。