在双功能RelA/SpoT同类体中对立的活性位点之间的形态对抗在严格反应期间调节 (p) p p Gpp代谢 [被纠正]
Tanis Hogg1, Undine Mechold, Horst Malke
1Laboratory of Molecular Genetics, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA.
Cell
|April 7, 2004
概括
细菌通过严格的反应,由Rel/Spo酶调节,在营养稀缺的情况下生存. 结构分析揭示了这些酶如何在合成和化警报激素之间切换 (p) pGpp.
科学领域:
- 生物化学 生物化学
- 分子生物学分子生物学
- 结构生物学 结构生物学
背景情况:
- 瑞尔/斯波酶产生警报激素 (p) ppGpp,触发细菌对营养限制的严格反应.
- 这种反应对于饥饿期间的细菌生存至关重要.
- 瑞尔/斯波蛋白具有双功能催化活性,可以合成和化 (p) pGpp.
研究的目的:
- 阐明Rel/Spo酶活动的相互调节的结构基础.
- 了解在分子水平上严格反应的机制.
主要方法:
- 来自Streptococcus dysgalactiae亚种的Rel/Spo同类Rel(Seq) 的X射线晶体学 它们是等同的. equisimilis.
- 分析酶构造和活性部位结构的分析.
- 针对位点的突变发生,以研究酶调节.
主要成果:
- 2.1 Å 晶体结构揭示了两个不同的酶构造,对应于合成酶-ON/酶-OFF 和合成酶-OFF/酶-ON 状态.
- 酶和合成酶域与循环化酶和核基转移酶超级家族有相似之处.
- 活性位点距离很远,但相互关联,具有结合的核酸,包括GDP-2':3'-循环单酸盐.
- 突变发生支持相互调节,涉及连接体诱导的信号传输.
结论:
- 该结构为Rel/Spo酶活动的相互调节提供了分子基础.
- 在活性位点之间由质诱导的信号传输可能控制了严格反应.
- 了解这种机制可以为针对细菌生存机制的策略提供信息.
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