首页> 外文OA文献 >Transcriptional Regulation of Divergent Capsule Biosynthesis and Transport Operon Promoters in Serogroup B Neisseria meningitidis
【2h】

Transcriptional Regulation of Divergent Capsule Biosynthesis and Transport Operon Promoters in Serogroup B Neisseria meningitidis

机译:B群脑膜炎奈瑟氏球菌不同胶囊生物合成和运输操纵子启动子的转录调控。

代理获取
本网站仅为用户提供外文OA文献查询和代理获取服务,本网站没有原文。下单后我们将采用程序或人工为您竭诚获取高质量的原文,但由于OA文献来源多样且变更频繁,仍可能出现获取不到、文献不完整或与标题不符等情况,如果获取不到我们将提供退款服务。请知悉。

摘要

The clinically important serogroups B, C, Y, and W-135 of Neisseria meningitidis produce sialic acid capsules that are critical in pathogenesis. In each of these serogroups, the capsule transport (ctrABCD) and capsule biosynthesis (synABCD) operons are divergently transcribed from putative promoters located in a 134-bp intergenic region (J. S. Swartley, J. H. Ahn, L. J. Liu, C. M. Kahler, and D. S. Stephens, J. Bacteriol. 178:4052–4059, 1996). In this study we further assessed the role of the intergenic sequence in the transcriptional regulation of the sialic acid capsules of N. meningitidis. Insertional mutagenesis or deletions of the 134-bp sequence in the serogroup B meningococcal strain NMB resulted in a marked reduction or elimination of ctrABCD and synABCD transcription, with a concomitant loss of encapsulation. Chromosomal transcriptional lacZ-ermC reporter fusions of syn and ctr promoters were constructed through allelic exchange. Using these constructs, both operons were found to be constitutively transcribed in meningococci, the biosynthesis operon about fourfold higher than the transport operon. Both promoters showed increased activity during stationary-phase growth. In addition to the promoters, a 70-bp 5′ untranslated region (UTR) upstream of synA was found to have a direct repeat and an inverted repeat that overlapped three putative integration host factor binding sites. Mutation of this 70-bp UTR and of the direct repeat upregulated both syn and ctr transcription. Regulation through the synA UTR was absent in a K1 Escherichia coli strain that produces identical capsular polysaccharide, implicating species-specific regulation. Meningococcal sialic acid capsule expression is initiated by divergent promoters in a 134-bp intergenic region, is repressed at the transcriptional level by the 5′ UTR of synA, is increased during stationary-phase growth, and shows species-specific regulation. Transcriptional regulation is another important control point for sialic capsule expression in N. meningitidis.
机译:脑膜炎奈瑟氏球菌的临床重要血清群B,C,Y和W-135会产生在发病机理中至关重要的唾液酸胶囊。在这些血清群中的每一个中,胶囊转运(ctrABCD)和胶囊生物合成(synABCD)操纵子都是从位于134 bp基因间区域的推定启动子(JS Swartley,JH Ahn,LJ Liu,CM Kahler和DS Stephens, J. Bacteriol。178:4052-4059,1996)。在这项研究中,我们进一步评估了基因间序列在脑膜炎奈瑟氏菌唾液酸胶囊转录调控中的作用。 B型脑膜炎球菌血清型NMB中134 bp序列的插入诱变或缺失导致ctrABCD和synABCD转录显着减少或消除,同时伴随着封装的丧失。通过等位基因交换构建了syn和ctr启动子的染色体转录lacZ-ermC报告基因融合体。使用这些构建体,发现两个操纵子在脑膜炎球菌中组成性转录,其生物合成操纵子比运输操纵子高约四倍。两种启动子在固定相生长期间均显示出增加的活性。除了启动子外,还发现synA上游的一个70 bp的5'非翻译区(UTR)具有一个直接重复和一个反向重复,与三个假定的整合宿主因子结合位点重叠。此70 bp UTR和直接重复序列的突变均上调了syn和ctr转录。在生产相同荚膜多糖的K1大肠埃希氏菌菌株中不存在通过synA UTR进行的调控,这涉及物种特异性调控。脑膜炎球菌唾液酸胶囊的表达是由一个134 bp的基因间区域中的不同启动子启动的,在syna的5'UTR的转录水平上受到抑制,在稳态生长期间增加,并显示出种特异性调节。转录调节是脑膜炎奈瑟氏菌中唾液胶囊表达的另一个重要控制点。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
代理获取

客服邮箱:kefu@zhangqiaokeyan.com

京公网安备:11010802029741号 ICP备案号:京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有
  • 客服微信

  • 服务号