• 主题
高级搜索  >
历史搜索 清空历史
首页> 美国卫生研究院文献>Journal of Bacteriology >Two Bifunctional Enzymes with Ferric Reduction Ability Play Complementary Roles during Magnetosome Synthesis in Magnetospirillum gryphiswaldense MSR-1
【2h】

Two Bifunctional Enzymes with Ferric Reduction Ability Play Complementary Roles during Magnetosome Synthesis in Magnetospirillum gryphiswaldense MSR-1

机译：两种具有铁还原能力的双功能酶在磁螺旋螺线虫MSR-1中的磁小体合成过程中发挥互补作用。

代理获取
本网站仅为用户提供外文OA文献查询和代理获取服务，本网站没有原文。下单后我们将采用程序或人工为您竭诚获取高质量的原文，但由于OA文献来源多样且变更频繁，仍可能出现获取不到、文献不完整或与标题不符等情况，如果获取不到我们将提供退款服务。请知悉。
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

The bacterial strain Magnetospirillum gryphiswaldense MSR-1 does not produce siderophores, but it absorbs a large amount of ferric iron and synthesizes magnetosomes. We demonstrated previously the presence of six types of ferric reductase isozymes (termed FeR1 through FeR6) in MSR-1. Of these isozymes, FeR5 was the most abundant and FeR6 showed the highest ferric reductase activity. In the present study, we cloned the fer5 and fer6 genes from MSR-1 and expressed them separately in Escherichia coli. FeR5 and FeR6 were shown to be bifunctional enzymes through analysis of amino acid sequence homologies, structural predictions (using data from GenBank), and detection of enzyme activities. FeR5 is a thioredoxin reductase and FeR6 is a flavin reductase, in addition to being ferric reductases. To elucidate the functions of the enzymes, we constructed two single-gene-deletion mutant strains (Δfer5 and Δfer6 mutants) and a double-gene-deletion mutant strain (Δfer5 Δfer6 [Δfer5+6] mutant) along with its complemented strains (C5 and C6). An evaluation of phenotypic and physiological properties did not reveal significant differences between the wild-type and single-gene-deletion strains, whereas the double-gene-deletion strain showed reduced iron absorption and no magnetosome synthesis. Complementation of the double-gene-deletion strain using either fer5 or fer6 resulted in the partial recovery of magnetosome synthesis. Quantitative real-time PCR analysis of fer5 and fer6 transcriptional levels in the wild-type and complemented strains demonstrated consistent transcription of the two genes and confirmed that FeR5 and FeR6 are bifunctional enzymes that play complementary roles during the process of magnetosome synthesis in MSR-1.
机译：细菌菌株Magnetospirillum gryphiswaldense MSR-1不会产生铁载体，但会吸收大量的三价铁并合成磁小体。我们先前证明了MSR-1中存在六种类型的铁还原酶同工酶（称为FeR1至FeR6）。在这些同工酶中，FeR5最丰富，FeR6显示最高的铁还原酶活性。在本研究中，我们从MSR-1克隆了fer5和fer6基因，并分别在大肠杆菌中表达。通过分析氨基酸序列同源性，结构预测（使用来自GenBank的数据）和检测酶活性，FeR5和FeR6被证明是双功能酶。除了是铁还原酶之外，FeR5是硫氧还蛋白还原酶，FeR6是黄素还原酶。为了阐明酶的功能，我们构建了两个单基因缺失突变株（Δfer5和Δfer6突变体）和双基因缺失突变株（Δfer5Δfer6[Δfer5+ 6]突变株）及其互补株（C5）和C6）。表型和生理特性的评估未发现野生型和单基因缺失菌株之间的显着差异，而双基因缺失菌株显示出铁吸收降低且没有磁小体合成。使用fer5或fer6对双基因缺失菌株的互补作用导致了磁小体合成的部分恢复。野生型和互补菌株中fer5和fer6转录水平的实时定量PCR分析证明了这两个基因的转录一致，并证实了FeR5和FeR6是双功能酶，在MSR-1的磁小体合成过程中起互补作用。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
代理获取

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