Organic cofactors in the metabolism of Dehalococcoides mccartyi strains
Organic cofactors in the metabolism of Dehalococcoides mccartyi strains
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DOI：
10.1098/rstb.2012.0321
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发表时间：
2013-04
期刊：
影响因子：
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通讯作者：
Christian J. Schipp;E. Marco-Urrea;Anja Kublik;J. Seifert;L. Adrian
中科院分区：
文献类型：
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作者：
Christian J. Schipp;E. Marco-Urrea;Anja Kublik;J. Seifert;L. Adrian
麦卡脱卤球菌属菌株是严格厌氧的生物体，专门通过呼吸过程以卤代化合物作为电子受体生长。它们的基因组是已知的自由生活的生物体中最小的，嵌入的基因组反映了它们强烈的专业化。在这里，我们简要回顾已发表的Dehalococcoides基因组的主要特点，并显示基因组信息与培养和生化实验，有助于我们了解Dehaloccoides的生理和生物化学。我们通过详细分析Dehalococcoides菌株CBDB 1中的辅因子代谢来扩展这种方法。对Dehalococcoides基因组进行筛选，以编码注释为含有有机辅因子或与有机辅因子相互作用的蛋白质，并通过鸟枪蛋白质组学分析这些蛋白质的表达，以阐明辅因子的要求。与此同时，对维生素需要量进行的培养试验表明，氰钴胺（维生素B12）、硫胺素和生物素是必不可少的补充剂，氰钴胺可以用二氰基钴胺和二甲基苯并咪唑取代。Dehalococcoides基因组分析，通过鸟枪蛋白质组学和抑制研究检测单酶，证实了菌株CBDB 1中吡哆醛-5-磷酸，黄素核苷酸，叶酸，S-腺苷甲硫氨酸，泛酸和烟酸的生物合成途径的表达。血红素/细胞色素，醌类和硫辛酸是不必要的培养或脱氯活性，并没有生物合成途径中的基因组。
Dehalococcoides mccartyi strains are strictly anaerobic organisms specialized to grow with halogenated compounds as electron acceptor via a respiratory process. Their genomes are among the smallest known for free-living organisms, and the embedded gene set reflects their strong specialization. Here, we briefly review main characteristics of published Dehalococcoides genomes and show how genome information together with cultivation and biochemical experiments have contributed to our understanding of Dehalococcoides physiology and biochemistry. We extend this approach by the detailed analysis of cofactor metabolism in Dehalococcoides strain CBDB1. Dehalococcoides genomes were screened for encoded proteins annotated to contain or interact with organic cofactors, and the expression of these proteins was analysed by shotgun proteomics to shed light on cofactor requirements. In parallel, cultivation experiments testing for vitamin requirements showed that cyanocobalamin (vitamin B12), thiamine and biotin were essential supplements and that cyanocobalamin could be substituted by dicyanocobinamide and dimethylbenzimidazole. Dehalococcoides genome analysis, detection of single enzymes by shotgun proteomics and inhibition studies confirmed the expression of the biosynthetic pathways for pyridoxal-5-phosphate, flavin nucleotides, folate, S-adenosylmethionine, pantothenate and nicotinic acids in strain CBDB1. Haem/cytochromes, quinones and lipoic acids were not necessary for cultivation or dechlorination activity and no biosynthetic pathways were identified in the genomes.