Discovery of a New Neisseria gonorrhoeae Type IV Pilus Assembly Factor, TfpC.
Discovery of a New Neisseria gonorrhoeae Type IV Pilus Assembly Factor, TfpC.
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DOI：
10.1128/mbio.02528-20
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发表时间：
2020-10-27
期刊：
影响因子：
6.4
通讯作者：
Seifert HS
中科院分区：
文献类型：
--
作者：
Hu LI;Yin S;Ozer EA;Sewell L;Rehman S;Garnett JA;Seifert HS
大多数细菌物种表达一种或多种称为菌毛/菌毛的细胞外细胞器，它们是每个细菌细胞的许多特性所必需的。 IV 型淋病奈瑟菌菌毛是性传播感染淋病的主要毒力和定植因子。我们发现了一种名为 TfpC 的淋病奈瑟菌新蛋白，它是维持细菌细胞表面 IV 型菌毛所必需的。在奈瑟菌属的其他成员和许多其他对人类健康重要的细菌物种中也发现了类似的蛋白质。淋病奈瑟菌依靠 IV 型菌毛 (T4p) 促进其人类宿主的定植并引起性传播感染淋病。这种细胞器通过延伸和缩回到细菌细胞的过程循环。通过基因筛选，我们鉴定出淋病奈瑟菌FA1090菌株的NGO0783基因座含有编码将IV型菌毛稳定在其延伸、非回缩构象所需的蛋白质的基因。我们将基因命名为 tfpC，将蛋白质命名为 TfpC。 tfpC 的缺失会产生无绒毛的菌落形态，免疫透射电子显微镜证实 ΔtfpC 突变体中菌毛丢失，尽管在细菌细胞表面附近检测到了一些菌毛蛋白。从 lac 启动子表达的 tfpC 基因的副本可恢复菌毛表达和相关表型。 ΔtfpC 突变体显示菌毛蛋白水平降低，但与 tfpC 基因的互补使菌毛蛋白恢复到正常水平。生物信息学搜索表明，许多细菌物种中都存在直向同源基因，但并非所有表达 IV 型菌毛蛋白的细菌都含有直向同源基因。协同进化和核磁共振 (NMR) 分析表明，TfpC 包含 N 端跨膜螺旋、大量延伸/非结构化区域和高电荷 C 端卷曲螺旋结构域。
Most bacterial species express one or more extracellular organelles called pili/fimbriae that are required for many properties of each bacterial cell. The Neisseria gonorrhoeae type IV pilus is a major virulence and colonization factor for the sexually transmitted infection gonorrhea. We have discovered a new protein of Neisseria gonorrhoeae called TfpC that is required to maintain type IV pili on the bacterial cell surface. There are similar proteins found in other members of the Neisseria genus and many other bacterial species important for human health. Neisseria gonorrhoeae relies on type IV pili (T4p) to promote colonization of their human host and to cause the sexually transmitted infection gonorrhea. This organelle cycles through a process of extension and retraction back into the bacterial cell. Through a genetic screen, we identified the NGO0783 locus of N. gonorrhoeae strain FA1090 as containing a gene encoding a protein required to stabilize the type IV pilus in its extended, nonretracted conformation. We have named the gene tfpC and the protein TfpC. Deletion of tfpC produces a nonpiliated colony morphology, and immuno-transmission electron microscopy confirms that the pili are lost in the ΔtfpC mutant, although there is some pilin detected near the bacterial cell surface. A copy of the tfpC gene expressed from a lac promoter restores pilus expression and related phenotypes. A ΔtfpC mutant shows reduced levels of pilin protein, but complementation with a tfpC gene restored pilin to normal levels. Bioinformatic searches show that there are orthologues in numerous bacterial species, but not all type IV pilin-expressing bacteria contain orthologous genes. Coevolution and nuclear magnetic resonance (NMR) analysis indicates that TfpC contains an N-terminal transmembrane helix, a substantial extended/unstructured region, and a highly charged C-terminal coiled-coil domain.