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对细菌类型IX分泌系统的C端信号域的结构和功能洞察力
Danuta Mizgalska1, Arturo Rodríguez-Banqueri2, Florian Veillard1
1Department of Microbiology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Kraków, Poland.
Open biology
|June 11, 2024
概括
细菌使用一种类型IX分泌系统 (T9SS),需要C端域 (CTD) 来进行蛋白质输出. 这些CTD中保存的图案对T9SS功能至关重要,防止跨物种干扰.
科学领域:
- 微生物学 微生物学
- 结构生物学 结构生物学
- 分子生物学分子生物学
背景情况:
- 细菌菌群中的グラム阴性细菌利用一种类型IX分泌系统 (T9SS).
- T9SS蛋白质分泌需要在货物蛋白上特定的C端域 (CTD).
- 以前的研究已经从 * Porphyromonas gingivalis * 蛋白质中鉴定出 CTD 的特征.
研究的目的:
- 调查T9SS中CTD的结构和功能意义.
- 为了在CTD中识别对T9SS介导的蛋白质分泌至关重要的保存基因.
- 探索CTD的物种特异性及其在防止T9SS交叉通话中的作用.
主要方法:
- 来自 * Porphyromonas gingivalis * 蛋白质 (RgpB, HBP35, PorU, PorZ) 的 CTD 的结构分析.
- 产生和分析具有改变CTD的突变菌株 (*P. gingivalis*) (插入,替换,切除,点突变).
- 一个*Tannerella forsythia* T9SS货物CTD (米罗拉) 的晶体结构的确定.
主要成果:
- 来自*P. gingivalis*的CTD共享了一个保存的免疫球蛋白类β-三明治结构.
- 特定的C-终端和循环动图 (C-t动图和Lβ3β4动图) 被确定为T9SS分泌的保存和功能相关.
- 来自*T.forsythia*的米罗拉的CTD共享了整体拓,但在动图Lβ3β4.4中缺乏保存.
- 化学蛋白实验表明,P. gingivalis和T. forsythia之间的CTDs不兼容.
结论:
- 在CTD中保存的β-sandwich架构和特定图案对于P. gingivalis*中的T9SS功能至关重要.
- *T.forsythia*CTDs的结构差异,特别是Lβ3β4动机的结构差异,有助于特定物种的T9SS活动.
- CTD不兼容性是防止不同细菌物种T9SS之间的干扰的机制.
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