两个截然不同的考古类型IV pili结构由相同的pilin形成
bioRxiv : the preprint server for biology
|August 23, 2023
概括
考古类型IV pili (T4P) 可以从相同的蛋白质中形成两个不同的结构. 在T4P组装中的这种灵活性允许在archaea中实现多种功能.
科学领域:
- 微生物学 微生物学
- 结构生物学 结构生物学
- 生物化学 生物化学
背景情况:
- 第四类 pili (T4P) 是常见的骨质表面附属物,涉及粘附,运动和通信.
- 这些纤维由柱状蛋白质组装在一起,可以延伸至微米长.
研究的目的:
- 确定从Saccharolobus islandicus* REY15A. REY15A. REY15A. REY15A. REY15A. REY15A. REY15A. REY15A. REY15A. REY15A. 的两个不同的T4P的原子结构.
- 为了研究相同的皮林蛋白如何在不同的条件下形成不同的丝状结构.
主要方法:
- 使用冷电子显微镜 (cryo-EM) 来确定 pili 的原子结构.
- 在单体和三体的皮林形状的比较分析.
主要成果:
- 确定了两个不同的T4P结构,单基和三基,两者都由相同的pilin蛋白组装在一起.
- 三柱体呈现出三种不同的柱体形状,具有显著的外部域旋转 (近180°),与单柱体的单一形状不同.
- 这两种pilus形式都使用相同的组装机械 (ATPase和TadC类孔),尽管基因表达不同.
结论:
- 同一个古老的T4P分泌系统可以产生结构多样化的纤维.
- 考古的T4P与考古的鞭毛纤维相比,具有更大的结构灵活性,这表明它们的形状受到更少的约束.
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