...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Journal of bacteriology >Requirement of Novel Competence Genes pilT andpilU of Pseudomonas stutzeri for Natural Transformation and Suppression of pilT Deficiency by a Hexahistidine Tag on the Type IV Pilus Protein PilAI
【24h】

Requirement of Novel Competence Genes pilT andpilU of Pseudomonas stutzeri for Natural Transformation and Suppression of pilT Deficiency by a Hexahistidine Tag on the Type IV Pilus Protein PilAI

机译：斯氏假单胞菌新能力基因pilT和pilU的自然转化和通过六组蛋白标签上的六组氨酸标签抑制pilT缺乏的要求

获取原文
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

The ubiquitous species Pseudomonas stutzeri has type IV pili, and these are essential for the natural transformation of the cells. An absolute transformation-deficient mutant obtained after transposon mutagenesis had an insertion in a gene which was termedpilT. The deduced amino acid sequence has identity with PilT of Pseudomonas aeruginosa (94%), Neisseria gonorrhoeae (67%), and other gram-negative species and it contains a nucleotide-binding motif. The mutant was hyperpiliated but defective for further pilus-associated properties, such as twitching motility and plating of pilus-specific phage PO4. [3H]thymidine-labeled DNA was bound by the mutant but not taken up. Downstream of pilT a gene, termedpilU, coding for a putative protein with 88% amino acid identity with PilU of P. aeruginosa was identified. Insertional inactivation did not affect piliation, twitching motility, or PO4 infection but reduced transformation to about 10%. The defect was fully complemented by PilU of nontransformable P. aeruginosa. When thepilAI gene (coding for the type IV pilus prepilin) was manipulated to code for a protein in which the six C-terminal amino acids were replaced by six histidine residues and then expressed from a plasmid, it gave a nonpiliated and twitching motility-defective phenotype in pilAI::Gmr cells but allowed transformability. Moreover, the mutant allele suppressed the absolute transformation deficiency caused by the pilT mutation. Considering the hypothesized role of pilT + in pilus retraction and the presumed requirement of retraction for DNA uptake, it is proposed that the pilT-independent transformation is promoted by PilA mutant protein either as single molecules or as minimal pilin assembly structures in the periplasm which may resemble depolymerized pili and that these cause the outer membrane pores to open for DNA entry.
机译：施氏假单胞菌无处不在的物种具有IV型菌毛，这些对于细胞的自然转化是必不可少的。转座子诱变后获得的绝对转化缺陷型突变体插入了一个名为 pilT 的基因。推导的氨基酸序列与铜绿假单胞菌（94％），淋病奈瑟菌（67％）和其他革兰氏阴性菌的PilT相同，并且含有一个核苷酸-结合基序。该突变体过度增生，但在菌毛相关的其他特性（如抽搐运动和菌毛特异性噬菌体PO4的铺板）方面存在缺陷。 [ 3 H]胸苷标记的DNA被突变体结合但未被吸收。 pilT 基因的下游，被称为 pilU ，该基因编码与88 PilU的88％氨基酸同一性的推定蛋白质。鉴定出铜绿。插入失活不会影响毛发，抽搐，蠕动或PO4感染，但可将转化率降低至约10％。该缺陷由不可转化的 P的PilU完全弥补。铜绿。当操作 pilAI 基因（编码IV型菌毛prepilin）来编码一种蛋白质，其中六个C末端氨基酸被六个组氨酸残基取代，然后从质粒表达时，在 pilAI :: Gm r 细胞中产生了非毛细和抽搐的运动缺陷型表型，但具有可转化性。此外，突变等位基因抑制了由 pilT 突变引起的绝对转化缺陷。考虑到 pilT + 在菌毛回缩中的假定作用以及对DNA摄取的回缩的假定要求，建议进行 pilT 独立转化PilA突变蛋白以单分子形式或周质中最小的菌毛蛋白组装结构促进了它的生长，这可能类似于解聚的菌毛，并导致外膜孔打开以进入DNA。

著录项

相似文献

  • 外文文献
获取原文

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