来自Methanosarcina barkeri的根性SAM血合成酶AhbD含有两个辅助的 [4Fe-4S] 集群
Isabelle Fix1, Lorenz Heidinger2, Thorsten Friedrich2
1Institut für Pharmazeutische Wissenschaften, Pharmazeutische Biologie, Albert-Ludwigs-Universität Freiburg, Stefan-Meier-Str. 19, 79104 Freiburg, Germany.
Biomolecules
|August 26, 2023
概括
在古生物和细菌中的血合成酶AhbD含有两个辅助铁硫,而不是一个. 这些集群对于结合中间体和生产中的电子转移至关重要.
科学领域:
- 生物化学 生物化学
- 微生物学 微生物学
- 酶学 是一种酶学.
背景情况:
- 在古生物和减少硫酸盐的细菌中,血红素合成依赖于依赖于血红素的血红素路径.
- 最后一步由激素SAM酶AhbD催化,将铁-甲氨酸III转化为heme.
- AhbD酶具有一个SPASM/Twitch域与辅助的铁硫集群.
研究的目的:
- 为了重新评估AhbD酶的辅助铁硫集群含量.
- 调查AhbD蛋白是否可以包含两个辅助铁硫集群 (AuxI和AuxII).
- 阐明这些集群在血红素合成中的作用.
主要方法:
- 氨基酸序列动图的生物信息分析和计算结构建模.
- 来自*Methanosarcina barkeri*缺乏个体的酶变体的生物化学表征.
- 光谱分析 (UV/可见吸收,EPR) 和铁/硫化物测定.
- 酶活性测定用于血合成酶的功能.
主要成果:
- 重新分析表明,一些AhbD蛋白质具有两个辅助集群 (AuxI和AuxII) 的动图.
- 生物化学和光谱学数据证实M. barkeri*的AhbD含有两个辅助的4Fe-4S集群.
- 血合成酶活性测定表明,AuxI与反应中间体结合,两个都参与电子转移.
结论:
- 来自M. barkeri的AhbD酶拥有两个辅助铁硫.
- 辅助集群在血合成过程中在基质结合和电子转移中起着重要作用.
- 这一发现扩大了对Radical SAM酶多样性和功能的理解.
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