Palchevskiy Vyacheslav, Finkel Steven E
Molecular and Computational Biology Program, Department of Biological Sciences, MCB 201B, University of Southern California, Los Angeles, CA 90089-2910, USA.
J Bacteriol. 2006 Jun;188(11):3902-10. doi: 10.1128/JB.01974-05.
Natural genetic competence is the ability of cells to take up extracellular DNA and is an important mechanism for horizontal gene transfer. Another potential benefit of natural competence is that exogenous DNA can serve as a nutrient source for starving bacteria because the ability to "eat" DNA is necessary for competitive survival in environments containing limited nutrients. We show here that eight Escherichia coli genes, identified as homologs of com genes in Haemophilus influenzae and Neisseria gonorrhoeae, are necessary for the use of extracellular DNA as the sole source of carbon and energy. These genes also confer a competitive advantage to E. coli during long-term stationary-phase incubation. We also show that homologs of these genes are found throughout the proteobacteria, suggesting that the use of DNA as a nutrient may be a widespread phenomenon.
自然遗传转化能力是细胞摄取细胞外DNA的能力，是水平基因转移的重要机制。自然转化能力的另一个潜在益处是，外源DNA可以作为饥饿细菌的营养源，因为在营养有限的环境中，“摄取”DNA的能力是竞争性生存所必需的。我们在此表明，八个大肠杆菌基因，被鉴定为流感嗜血杆菌和淋病奈瑟菌中com基因的同源物，是将细胞外DNA用作唯一碳源和能源所必需的。这些基因在长期稳定期培养过程中也赋予大肠杆菌竞争优势。我们还表明，这些基因的同源物在整个变形菌门中都能找到，这表明将DNA用作营养物质可能是一种广泛存在的现象。
