Gain and loss of the gonococcal genetic island in Neisseria

奈瑟氏球菌淋球菌遗传岛的得失

• 批准号: 7313546
• 负责人: Joseph P Dillard
• 金额: $ 18万
• 依托单位: UNIVERSITY OF WISCONSIN-MADISON
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-07-15 至 2009-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7313546
• 关键词: Affect; Autolysis; Bacteria; Cell Line; Cells; Cervical; Chromosomes; Coculture Techniques; Cytolysis; DNA; DNA Sequence; Data; Defect; Endothelial Cells; Epithelial; Escherichia coli; Excision; Exhibits; Frequencies; Genes; Genetic; Genetic Recombination; Gonorrhea; Homologous Gene; Human; Human Cell Line; Immunologic Surveillance; Infection; Investigation; Island; Knowledge; Membrane; Membrane Proteins; Mobile Genetic Elements; Modeling; Mutagenesis; Mutation; Neisseria; Neisseria gonorrhoeae; Neisseria meningitidis; Peptidoglycan; Phenotype; Population; Proteins; Relative (related person); Resolution; Role; Site; Surface; Testing; Time; Type IV Secretion System Pathway; Variant; design; dimer; homologous recombination; insertion/deletion mutation; interest; mutant; pathogen; recombinase; research study

DESCRIPTION (provided by applicant): The gonococcal genetic island (GGI) is a 57 kb region of DNA that is found in the chromosomes of 80% of Neisseria gonorrhoeae strains and was recently identified in Neisseria meningitidis. The GGI sequence shows evidence that it was horizontally acquired from another bacterial species. It is flanked by a 23-bp repeat, one copy of which makes up most of the dif site at the gonococcal replication terminus. The second copy of the repeat is part of an imperfect copy of the dif sequence. dif is a sequence that is recognized by the site-specific recombinase XerCD. In E. coli it has been shown that dif and XerCD facilitate the resolution of chromosomal dimers that result from homologous recombination following chromosomal replication. The identification of the GGI in N. meningitidis suggests that the GGI may be horizontally transferred between Neisseria species. This proposal describes experiments to characterize the mechanisms involved in acquisition and excision of the GGI and the phenotypes associated with acquisition of the GGI by N. meningitidis strains. Characterization of GGI loss in N. gonorrhoeae indicates that the dif sequence facilitates excision by site-specific recombination. Limited DNA sequence information on the GGI from several N. meningitidis isolates identifies type IV secretion system genes in the meningococcal isolates, but that certain putative surface components exist in variant forms. These data suggest that the type IV secretion system may function differently in N. meningitidis and may be subject to immune surveillance. These studies will further characterize the gene content of the N. meningitidis GGIs and examine their effects on infection of human cells in culture. This proposal describes experiments to characterize the mechanisms involved in acquisition and excision of the GGI and the phenotypes associated with acquisition of the GGI by N. meningitidis strains. These studies will further characterize the gene content of the N. meningitidis GGIs and examine their effects on infection of human cells in culture.

描述（由申请人提供）：淋球菌遗传岛（GGI）是一个57 kb的DNA区域，在80％的淋病奈瑟氏菌染色体中发现，最近在奈瑟氏菌中鉴定出来。 GGI序列显示了证据表明它是从其他细菌物种中水平获取的。它的侧面是23 bp重复，其中一个副本构成了淋球菌复制末端的大部分DIF位点。重复的第二副本是差异序列不完美副本的一部分。 DIF是由位点特异性重组酶XERCD识别的序列。在大肠杆菌中，已经表明，DIF和XERCD促进了染色体复制后同源重组产生的染色体二聚体的分辨率。脑膜炎链球菌中GGI的鉴定表明，GGI可以水平转移到奈瑟氏菌中。 该提案描述了表征GGI获取和切除涉及的机制的实验以及与脑膜炎N.脑膜菌菌株获得GGI相关的表型。淋病猪笼草中GGI损失的表征表明，差异序列有助于通过位点特异性重组切除。有限的DNA序列信息来自几个脑膜炎分离株的GGI，可以鉴定脑膜炎球菌分离株中IV型分泌系统基因，但某些假定的表面成分以变异形式存在。这些数据表明，IV型分泌系统在脑膜炎林杆菌中的起作用可能不同，并且可能受到免疫监视。这些研究将进一步表征脑膜炎猪笼草的基因含量，并检查其对培养物中人类细胞感染的影响。 该提案描述了表征GGI获取和切除涉及的机制的实验以及与脑膜炎N.脑膜菌菌株获得GGI相关的表型。这些研究将进一步表征脑膜炎猪笼草的基因含量，并检查其对培养物中人类细胞感染的影响。