Comparative genomic analysis of magnetotactic bacteria from the Deltaproteobacteria provides new insights into magnetite and greigite magnetosome genes required for magnetotaxis
Comparative genomic analysis of magnetotactic bacteria from the Deltaproteobacteria provides new insights into magnetite and greigite magnetosome genes required for magnetotaxis
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DOI：
10.1111/1462-2920.12128
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发表时间：
2013-10-01
影响因子：
5.1
通讯作者：
Ginet, Nicolas
中科院分区：
文献类型：
--
作者：
Lefevre, Christopher T.;Trubitsyn, Denis;Ginet, Nicolas
趋磁细菌（MTB）代表了一组不同的运动原核生物，生物矿化磁小体，负责趋磁性的细胞器。磁小体由细胞内的、膜结合的、数十纳米大小的磁性矿物磁铁矿（Fe 3 O 4）或硫铁矿（Fe 3 S4）晶体组成，通常在细胞内组织为链，就像指南针一样。大多数关于磁小体形成所涉及的生物矿化过程的信息来自于涉及Alphaproteobacteria物种的研究，该物种使磁铁矿的立方八面体和细长棱柱晶体生物矿化。在这些生物体中鉴定的许多磁小体基因（mam基因）在所有已知的MTB中是保守的。在这里，我们提出了一个比较基因组分析的趋磁Deltaproteobacteria，合成子弹形晶体的磁铁矿和/或硫铁矿。我们发现，除了mam基因，有一组保守的基因，指定的疯狂的基因，特定的趋磁Deltaproteobacteria，一些也存在于nitrosspiphylum的bavaricum，但没有在趋磁Alphaproteobacteria。我们的研究结果表明，与趋磁性Deltaproteobacteria中的趋磁性相关的基因的数量比以前认为的要大。我们还表明，磁小体形成所需的最小一套MAM基因在磁细菌也是保守的产磁铁矿，趋磁Deltaproteobacteria。一些假定的新功能的mad基因进行了讨论。
Magnetotactic bacteria (MTB) represent a group of diverse motile prokaryotes that biomineralize magnetosomes, the organelles responsible for magnetotaxis. Magnetosomes consist of intracellular, membrane-bounded, tens-of-nanometre-sized crystals of the magnetic minerals magnetite (Fe3O4) or greigite (Fe3S4) and are usually organized as a chain within the cell acting like a compass needle. Most information regarding the biomineralization processes involved in magnetosome formation comes from studies involving Alphaproteobacteria species which biomineralize cuboctahedral and elongated prismatic crystals of magnetite. Many magnetosome genes, the mam genes, identified in these organisms are conserved in all known MTB. Here we present a comparative genomic analysis of magnetotactic Deltaproteobacteria that synthesize bullet-shaped crystals of magnetite and/or greigite. We show that in addition to mam genes, there is a conserved set of genes, designated mad genes, specific to the magnetotactic Deltaproteobacteria, some also being present in CandidatusMagnetobacterium bavaricum of the Nitrospirae phylum, but absent in the magnetotactic Alphaproteobacteria. Our results suggest that the number of genes associated with magnetotaxis in magnetotactic Deltaproteobacteria is larger than previously thought. We also demonstrate that the minimum set of mam genes necessary for magnetosome formation in Magnetospirillum is also conserved in magnetite-producing, magnetotactic Deltaproteobacteria. Some putative novel functions of mad genes are discussed.