Mechanisms and evolution of oxidative sulfur metabolism in green sulfur bacteria.
Mechanisms and evolution of oxidative sulfur metabolism in green sulfur bacteria.
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DOI：
10.3389/fmicb.2011.00116
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发表时间：
2011
影响因子：
5.2
通讯作者：
Frigaard NU
中科院分区：
文献类型：
--
作者：
Gregersen LH;Bryant DA;Frigaard NU
绿色硫磺细菌(GSB)是一类表型变异有限的光自养细菌和硫代营养细菌，具有紧密的亲缘关系。它们通常以硫球为中间体，将硫化物和硫代硫酸盐氧化成硫酸盐。根据15个菌株的基因组序列信息，对其硫氧化代谢相关酶的分布和系统发育进行了研究。所有菌株中至少存在一种硫化物的同源物：苯醌氧化还原酶(SQR)。在所有硫氧化GSB菌株中，除最早发散的氯二氢钾外，硫化物氧化产物被异化亚硫酸盐还原酶(DSR)系统进一步氧化为亚硫酸盐。该系统由横向部分来自硫化物氧化和部分来自硫酸盐还原细菌的组分组成。根据菌株的不同，亚硫酸盐可能被两种不同的机制之一氧化成硫酸盐，这两种机制具有不同的进化起源：腺苷-5‘-磷酸硫酸盐还原酶或多硫化物还原酶复合体3。硫代硫酸盐在GSB中的利用显然是从变形杆菌水平获得的。在GSB中不存在SoxCD，它在其他细菌中形成硫酸盐的功能已被GSB中的DSR系统所取代。序列分析表明，这一保守的soxJXYZAKBW基因簇是由褐弧菌DSM 265从绿杆菌谱系中水平获得的，这种获得是由一个可移动的遗传元件介导的。因此，目前已知的GSB的最后一个共同祖先可能是光自养、水遗传营养的，并且含有SQR，而不是DSR或SOX。此外，绿细菌-绿杆菌-原氯菌在培养的GSB中的优势可能是由于水平获得的DSR和SOX系统。最后，基于结构、生化和系统发育分析，建议对原核生物中的SQR基因进行统一的命名。
Green sulfur bacteria (GSB) constitute a closely related group of photoautotrophic and thiotrophic bacteria with limited phenotypic variation. They typically oxidize sulfide and thiosulfate to sulfate with sulfur globules as an intermediate. Based on genome sequence information from 15 strains, the distribution and phylogeny of enzymes involved in their oxidative sulfur metabolism was investigated. At least one homolog of sulfide:quinone oxidoreductase (SQR) is present in all strains. In all sulfur-oxidizing GSB strains except the earliest diverging Chloroherpeton thalassium, the sulfide oxidation product is further oxidized to sulfite by the dissimilatory sulfite reductase (DSR) system. This system consists of components horizontally acquired partly from sulfide-oxidizing and partly from sulfate-reducing bacteria. Depending on the strain, the sulfite is probably oxidized to sulfate by one of two different mechanisms that have different evolutionary origins: adenosine-5′-phosphosulfate reductase or polysulfide reductase-like complex 3. Thiosulfate utilization by the SOX system in GSB has apparently been acquired horizontally from Proteobacteria. SoxCD does not occur in GSB, and its function in sulfate formation in other bacteria has been replaced by the DSR system in GSB. Sequence analyses suggested that the conserved soxJXYZAKBW gene cluster was horizontally acquired by Chlorobium phaeovibrioides DSM 265 from the Chlorobaculum lineage and that this acquisition was mediated by a mobile genetic element. Thus, the last common ancestor of currently known GSB was probably photoautotrophic, hydrogenotrophic, and contained SQR but not DSR or SOX. In addition, the predominance of the Chlorobium–Chlorobaculum–Prosthecochloris lineage among cultured GSB could be due to the horizontally acquired DSR and SOX systems. Finally, based upon structural, biochemical, and phylogenetic analyses, a uniform nomenclature is suggested for sqr genes in prokaryotes.
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影响因子：
3.7
作者：
Chew, Aline Gomez Maqueo;Frigaard, Niels-Ulrik;Bryant, Donald A.
通讯作者：
Bryant, Donald A.
影响因子：
4.2
作者：
Gregersen, Lea H.;Habicht, Kirsten S.;Frigaard, Niels-Ulrik
通讯作者：
Frigaard, Niels-Ulrik
影响因子：
2.9
作者：
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通讯作者：
Archer, Margarida
影响因子：
3.7
作者：
Azai, Chihiro;Tsukatani, Yusuke;Oh-oka, Hirozo
通讯作者：
Oh-oka, Hirozo
影响因子：
2.8
作者：
GIBSON, J;PFENNIG, N;WATERBURY, JB
通讯作者：
WATERBURY, JB