Knock-out of SO1377 gene, which encodes the member of a conserved hypothetical bacterial protein family COG2268, results in alteration of iron metabolism, increased spontaneous mutation and hydrogen peroxide sensitivity in Shewanella oneidensis MR-1.
Knock-out of SO1377 gene, which encodes the member of a conserved hypothetical bacterial protein family COG2268, results in alteration of iron metabolism, increased spontaneous mutation and hydrogen peroxide sensitivity in Shewanella oneidensis MR-1.
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DOI：
10.1186/1471-2164-7-76
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发表时间：
2006-04-06
期刊：
影响因子：
4.4
通讯作者：
Zhou J
中科院分区：
文献类型：
--
作者：
Gao W;Liu Y;Giometti CS;Tollaksen SL;Khare T;Wu L;Klingeman DM;Fields MW;Zhou J
希瓦氏菌MR-1是一种兼性革兰氏阴性细菌，能够将有机碳的氧化偶联到广泛的电子受体，如氧、硝酸盐和金属，并具有重金属污染场所的生物修复潜力。测序结果显示，该菌株MR-1基因组约有42%编码功能未知的蛋白质。定义假设蛋白质的功能是一个巨大的挑战，可能需要一个系统的方法。在这项研究中，我们采用全基因组芯片和蛋白质组学的综合方法，研究了编码SO1377 （gi24372955）的基因在不同生理条件下的敲除效应。SO1377 （gi24372955）是一个保守的、假设的细菌蛋白家族COG2268（簇同源群）的成员。与野生型菌株相比，生长试验表明，缺失突变体在好氧培养条件下生长速度下降，但在厌氧条件下不受影响。全基因组表达（RNA和蛋白质）谱显示，与野生型对照相比，许多基因和蛋白质的表达发生了变化，包括一些与铁代谢、氧化损伤保护和呼吸电子转移有关的基因和蛋白质，如呼吸链复合体IV。尽管细胞内总铁水平保持不变，但全细胞电子顺磁共振（EPR）显示，突变细胞中的游离铁水平比野生型菌株低3倍。在缺铁培养基中，突变体的铁细胞排泄量也减少。该突变体对过氧化氢更敏感，对庆大霉素或卡那霉素耐药的菌落增加了100倍。结果表明，SO1377基因的敲除具有多效性，提示SO1377可能在铁稳态和氧化损伤保护中发挥作用。
Shewanella oneidensis MR-1 is a facultative, gram-negative bacterium capable of coupling the oxidation of organic carbon to a wide range of electron acceptors such as oxygen, nitrate and metals, and has potential for bioremediation of heavy metal contaminated sites. The complete 5-Mb genome of S. oneidensis MR-1 was sequenced and standard sequence-comparison methods revealed approximately 42% of the MR-1 genome encodes proteins of unknown function. Defining the functions of hypothetical proteins is a great challenge and may need a systems approach. In this study, by using integrated approaches including whole genomic microarray and proteomics, we examined knockout effects of the gene encoding SO1377 (gi24372955), a member of the conserved, hypothetical, bacterial protein family COG2268 (Clusters of Orthologous Group) in bacterium Shewanella oneidensis MR-1, under various physiological conditions. Compared with the wild-type strain, growth assays showed that the deletion mutant had a decreased growth rate when cultured aerobically, but not affected under anaerobic conditions. Whole-genome expression (RNA and protein) profiles revealed numerous gene and protein expression changes relative to the wild-type control, including some involved in iron metabolism, oxidative damage protection and respiratory electron transfer, e. g. complex IV of the respiration chain. Although total intracellular iron levels remained unchanged, whole-cell electron paramagnetic resonance (EPR) demonstrated that the level of free iron in mutant cells was 3 times less than that of the wild-type strain. Siderophore excretion in the mutant also decreased in iron-depleted medium. The mutant was more sensitive to hydrogen peroxide and gave rise to 100 times more colonies resistant to gentamicin or kanamycin. Our results showed that the knock-out of SO1377 gene had pleiotropic effects and suggested that SO1377 may play a role in iron homeostasis and oxidative damage protection in S. oneidensis MR-1.
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影响因子：
3.1
作者：
DONNENBERG, MS;KAPER, JB
通讯作者：
KAPER, JB
影响因子：
11.4
作者：
Kihara, A;Akiyama, Y;Ito, K
通讯作者：
Ito, K
影响因子：
3.5
作者：
Li, DS;Ohshima, K;Pandolfo, M
通讯作者：
Pandolfo, M
影响因子：
3.5
作者：
MADEJ, T;BOGUSKI, MS;BRYANT, SH
通讯作者：
BRYANT, SH
DOI：
10.1111/j.1749-6632.1999.tb07814.x
发表时间：
1999-01-01
期刊：
OXIDATIVE/ENERGY METABOLISM IN NEURODEGENERATIVE DISORDERS
影响因子：
--
作者：
Fridovich, I
通讯作者：
Fridovich, I