...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Proceedings of the National Academy of Sciences of the United States of America >Vitamin B1 biosynthesis in plants requires the essential iron-sulfur cluster protein, THIC
【24h】

Vitamin B1 biosynthesis in plants requires the essential iron-sulfur cluster protein, THIC

机译：植物中维生素B1的生物合成需要必需的铁硫簇蛋白THIC

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Vitamin B1 (thiamin) is an essential compound in all organisms acting as a cofactor in key metabolic reactions and has furthermore been implicated in responses to DNA damage and pathogen attack in plants. Despite the fact that it was discovered almost a century ago and deficiency is a widespread health problem, much remains to be deciphered about its biosynthesis. The vitamin is composed of a thiazole and pyrimidine heterocycle, which can be synthesized by prokaryotes, fungi, and plants. Plants are the major source of the vitamin in the human diet, yet little is known about the biosynthesis of the compound therein. In particular, it has never been verified whether the pyrimidine heterocycle is derived from purine biosynthesis through the action of the THIC protein as in bacteria, rather than vitamin B6 and histidine as demonstrated for fungi. Here, we identify a homolog of THIC in Arabidopsis and demonstrate its essentiality not only for vitamin B1 biosynthesis, but also plant viability. This step takes place in the chloroplast and appears to be regulated at several levels, including through the presence of a riboswitch in the 3-untranslated region of THIC. Strong evidence is provided for the involvement of an iron-sulfur cluster in the remarkable chemical rearrangement reaction catalyzed by the THIC protein for which there is no chemical precedent. The results suggest that vitamin B1 biosynthesis in plants is in fact more similar to prokaryotic counterparts and that the THIC protein is likely to be the key regulatory protein in the pathway.
机译：维生素B1（硫胺素）是所有生物体中重要代谢反应中的辅因子的必需化合物，此外还涉及植物对DNA损伤和病原体侵袭的反应。尽管事实上它是在一个世纪前发现的，而缺乏症是一个普遍存在的健康问题，但有关其生物合成的知识还有很多。维生素由噻唑和嘧啶杂环组成，可以由原核生物，真菌和植物合成。植物是人类饮食中维生素的主要来源，但其中的化合物的生物合成知之甚少。特别地，从未证实嘧啶杂环是否通过THIC蛋白的作用如细菌中那样通过嘌呤生物合成而衍生，而不是如真菌所证明的那样是由维生素B6和组氨酸衍生而来。在这里，我们确定了拟南芥中THIC的同系物，并证明了其不仅对于维生素B1的生物合成至关重要，而且对植物的生存能力也至关重要。该步骤发生在叶绿体中，并且似乎在几个水平上受到调节，包括通过在THIC的3个非翻译区中存在核糖开关。有力的证据表明，铁-硫簇参与了THIC蛋白催化的显着化学重排反应，目前尚无化学先例。结果表明，植物中维生素B1的生物合成实际上与原核生物类似，并且THIC蛋白可能是该途径中的关键调控蛋白。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号