...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Journal of bacteriology >In Helicobacter pylori, LuxS Is a Key Enzyme in Cysteine Provision through a Reverse Transsulfuration Pathway
【24h】

In Helicobacter pylori, LuxS Is a Key Enzyme in Cysteine Provision through a Reverse Transsulfuration Pathway

机译：在幽门螺杆菌中，LuxS是通过反向转硫途径提供半胱氨酸的关键酶。

获取原文
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

In many bacteria, LuxS functions as a quorum-sensing molecule synthase. However, it also has a second, more central metabolic function in the activated methyl cycle (AMC), which generates the S-adenosylmethionine required by methyltransferases and recycles the product via methionine. Helicobacter pylori lacks an enzyme catalyzing homocysteine-to-methionine conversion, rendering the AMC incomplete and thus making any metabolic role of H. pylori LuxS (LuxSHp) unclear. Interestingly, luxSHp is located next to genes annotated as cysKHp and metBHp, involved in other bacteria in cysteine and methionine metabolism. We showed that isogenic strains carrying mutations in luxSHp, cysKHp, and metBHp could not grow without added cysteine (whereas the wild type could), suggesting roles in cysteine synthesis. Growth of the ΔluxSHp mutant was restored by homocysteine or cystathionine and growth of the ΔcysKHp mutant by cystathionine only. The ΔmetBHp mutant had an absolute requirement for cysteine. Metabolite analyses showed that S-ribosylhomocysteine accumulated in the ΔluxSHp mutant, homocysteine in the ΔcysKHp mutant, and cystathionine in the ΔmetBHp mutant. This suggests that S-ribosylhomocysteine is converted by LuxSHp to homocysteine (as in the classic AMC) and thence by CysKHp to cystathionine and by MetBHp to cysteine. In silico analysis suggested that cysK-metB-luxS were acquired by H. pylori from a Gram-positive source. We conclude that cysK-metB-luxS encode the capacity to generate cysteine from products of the incomplete AMC of H. pylori in a process of reverse transsulfuration. We recommend that the misnamed genes cysKHp and metBHp be renamed mccA (methionine-to-cysteine-conversion gene A) and mccB, respectively.
机译：在许多细菌中，LuxS充当群体感应分子合酶。但是，它在激活的甲基循环（AMC）中还具有第二个更重要的中心代谢功能，该功能产生甲基转移酶所需的 S -腺苷甲硫氨酸，并通过甲硫氨酸回收产物。 幽门螺杆菌缺乏催化高半胱氨酸向蛋氨酸转化的酶，导致AMC不完全，从而使 H发挥任何代谢作用。幽门螺杆菌LuxS（LuxS Hp ）尚不清楚。有趣的是， luxS Hp 位于标注为 cysK Hp 和 metB 的基因旁边。 Hp ，参与半胱氨酸和蛋氨酸代谢中的其他细菌。我们显示了在 luxS Hp ， cysK Hp 和 metB 中带有突变的等基因菌株> Hp 在不添加半胱氨酸的情况下不能生长（而野生型可以），这表明在半胱氨酸合成中的作用。高半胱氨酸或胱硫醚可恢复Δ luxS Hp 突变体的生长，而Δ cysK Hp 突变体的生长可通过半胱氨酸或半胱氨酸恢复。仅胱硫醚。 Δ metB Hp 突变体对半胱氨酸具有绝对的需求。代谢物分析表明， S -核糖同型半胱氨酸积累在Δ luxS Hp 突变体中，同型半胱氨酸积累在Δ cysK Hp 突变体和Δ metB Hp 突变体中的胱硫醚。这表明 S -核糖基同型半胱氨酸被LuxS Hp 转化为高半胱氨酸（与经典AMC中一样），然后被CysK Hp 转化为胱硫醚，并被MetB Hp 变为半胱氨酸。 in silico 分析表明 cysK-metB-luxS 被 H获得。幽门螺杆菌（来自革兰氏阳性来源）。我们得出的结论是， cysK-metB-luxS 编码了从 H的不完全AMC产物生成半胱氨酸的能力。幽门螺杆菌的过程中。我们建议将名称错误的基因 cysK Hp 和 metB Hp 重命名为 mccA （甲硫氨酸到半胱氨酸的转化基因A）和 mccB 。

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