对LTA D-alanylation中DltB的传输和催化机制的结构洞察
1Cancer Center, Renmin Hospital of Wuhan University, Wuhan, China. pingfeng.zhang@whu.edu.cn.
Nature communications
|April 22, 2024
概括
热杆菌DltB形成一个四聚体,对脂铁醇酸 (LTA) 的D-化至关重要. 这种由冷EM可视化的结构,揭示了细菌细胞壁稳定性和潜在的抗病毒药物点的洞察力.
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:
- DltB是一种膜结合的O-转移酶 (MBOAT),对于格拉姆阳性细菌中利波铁酸 (LTA) 的D-化至关重要.
- LTA 修饰会影响细胞壁完整性,细菌毒性和宿主免疫相互作用.
- 人们对DltB活动的确切功能和结构基础的理解尚不完全.
研究的目的:
- 为了阐明Streptococcus thermophilus DltB. 的结构和功能.
- 研究D-alanylation通路中的DltB的机制.
- 为了确定抗病毒性疗法的潜在目标.
主要方法:
- 生物化学分析 生物化学分析
- 低温电子显微镜 (cryo-EM) 对DLTB在各种状态中的成像 (apo,与DLTC复合,与抑制剂m-AMSA复合).
主要成果:
- DltB 在细菌细胞膜上形成 homo-tetramer,其中有一个中央孔.
- 结构分析显示每个原质体内有不同的C和L道.
- DltB 结合了 DltC 和它的抑制剂 amsacrine (m-AMSA),并确定了一个潜在的 LTA 载体 (脂糖醇).
- 四重体结构促进了D-alananyl的转移,并调节了通道活动.
结论:
- DltB的四度组织对于其催化活性和D-alanylation通路中的调节至关重要.
- DltB在催化D-化和潜在地调节基质访问方面表现出双重作用.
- 向DltB为开发新型抗病毒抗生素提供了一个有前途的战略.
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