蓝B可以食用黄素,形成维生素B12的下层连接体
Michiko E Taga1, Nicholas A Larsen, Annaleise R Howard-Jones
1Department of Biology, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA.
Nature
|March 23, 2007
概括
该BluB酶碎片化flavin mononucleotide,以产生5,6-二甲基胺醇 (DMB),这是维生素B12的关键成分. 这一发现澄清了维生素B12生物合成及其相关疾病中缺失的一步.
科学领域:
- 生物化学 生物化学
- 微生物学 微生物学
- 结构生物学 结构生物学
背景情况:
- 维生素B12 (科巴胺) 是一种大型的,微生物合成的天然产品.
- 其较低的配体5,6-二甲基胺醇 (DMB) 的生物合成尚不清楚.
- 最近发现,来自Sinorhizobium meliloti的bluB基因对于DMB的产生至关重要.
研究的目的:
- 阐明BluB酶合成DMB的生物化学机制.
- 了解BluB独特的酶活性的结构基础.
主要方法:
- 生物化学测试研究BluB的酶活性.
- 对BluB和反应中间体进行晶体分析.
- 与相关的氧化还原酶酶的结构比较.
主要成果:
- 蓝B催化了flavin mononucleotide (FMN) 的碎片化和收缩,产生DMB和D-红4-酸盐.
- 结构分析显示,BluB与FMN紧密结合,与NAD(P) H-黄氧化降解酶不同.
- 晶体学捕获了一种中间体,显示分子氧被减少的黄素激活,用于反应.
结论:
- 蓝B使用了一种新的机制,涉及到FMN的自我食来产生DMB.
- 这项工作澄清了维生素B12生物合成中的重大差距.
- 了解这种途径可能有助于解决与维生素B12相关的疾病.
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