首页> 美国卫生研究院文献>Journal of Bacteriology >Nonredundant Roles for Cytochrome c2 and Two High-Potential Iron-Sulfur Proteins in the Photoferrotroph Rhodopseudomonas palustris TIE-1
【2h】

Nonredundant Roles for Cytochrome c2 and Two High-Potential Iron-Sulfur Proteins in the Photoferrotroph Rhodopseudomonas palustris TIE-1

机译:细胞色素c2和两个高电位铁硫蛋白在光铁营养性红假单胞菌TIE-1中的非冗余作用

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。
获取外文期刊封面目录资料

摘要

The purple bacterium Rhodopseudomonas palustris TIE-1 expresses multiple small high-potential redox proteins during photoautotrophic growth, including two high-potential iron-sulfur proteins (HiPIPs) (PioC and Rpal_4085) and a cytochrome c2. We evaluated the role of these proteins in TIE-1 through genetic, physiological, and biochemical analyses. Deleting the gene encoding cytochrome c2 resulted in a loss of photosynthetic ability by TIE-1, indicating that this protein cannot be replaced by either HiPIP in cyclic electron flow. PioC was previously implicated in photoferrotrophy, an unusual form of photosynthesis in which reducing power is provided through ferrous iron oxidation. Using cyclic voltammetry (CV), electron paramagnetic resonance (EPR) spectroscopy, and flash-induced spectrometry, we show that PioC has a midpoint potential of 450 mV, contains all the typical features of a HiPIP, and can reduce the reaction centers of membrane suspensions in a light-dependent manner at a much lower rate than cytochrome c2. These data support the hypothesis that PioC linearly transfers electrons from iron, while cytochrome c2 is required for cyclic electron flow. Rpal_4085, despite having spectroscopic characteristics and a reduction potential similar to those of PioC, is unable to reduce the reaction center. Rpal_4085 is upregulated by the divalent metals Fe(II), Ni(II), and Co(II), suggesting that it might play a role in sensing or oxidizing metals in the periplasm. Taken together, our results suggest that these three small electron transfer proteins perform different functions in the cell.
机译:紫色细菌Rhodopseudomonas palustris TIE-1在光合自养生长期间表达多种小的高电位氧化还原蛋白,包括两个高电位铁硫蛋白(HiPIP)(PioC和Rpal_4085)和细胞色素c2。我们通过遗传,生理和生化分析评估了这些蛋白质在TIE-1中的作用。删除编码细胞色素c2的基因会导致TIE-1丧失光合作用能力,表明该蛋白不能在循环电子流中被任何一个HiPIP取代。 PioC以前与光铁蛋白有关,光铁蛋白是一种不寻常的光合作用形式,其中通过亚铁氧化提供还原能力。使用循环伏安法(CV),电子顺磁共振(EPR)光谱和闪光感应光谱法,我们显示PioC具有450 mV的中点电位,包含HiPIP的所有典型特征,并且可以减少膜的反应中心以光依赖性方式悬浮,其速率远低于细胞色素c2。这些数据支持以下假设:PioC线性转移铁中的电子,而循环电子流需要细胞色素c2。 Rpal_4085尽管具有类似于PioC的光谱特征和还原电位,却无法还原反应中心。 Rpal_4085由二价金属Fe(II),Ni(II)和Co(II)上调,表明Rpal_4085可能在周质中感测或氧化金属中发挥作用。两者合计,我们的结果表明这三种小电子转移蛋白在细胞中执行不同的功能。

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