Lewis Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA.
Science. 2012 Jul 27;337(6093):470-3. doi: 10.1126/science.1219861. Epub 2012 Jul 8.
A strain of Halomonas bacteria, GFAJ-1, has been claimed to be able to use arsenate as a nutrient when phosphate is limiting and to specifically incorporate arsenic into its DNA in place of phosphorus. However, we have found that arsenate does not contribute to growth of GFAJ-1 when phosphate is limiting and that DNA purified from cells grown with limiting phosphate and abundant arsenate does not exhibit the spontaneous hydrolysis expected of arsenate ester bonds. Furthermore, mass spectrometry showed that this DNA contains only trace amounts of free arsenate and no detectable covalently bound arsenate.
一种名为 Halomonas 的细菌菌株 GFAJ-1 据称在磷酸盐有限的情况下能够利用砷酸盐作为营养物质，并将砷专门掺入其 DNA 中代替磷。然而，我们发现当磷酸盐有限时，砷酸盐不会促进 GFAJ-1 的生长，并且从在有限的磷酸盐和丰富的砷酸盐中生长的细胞中纯化的 DNA 没有表现出预期的砷酸盐酯键的自发水解。此外，质谱分析表明，这种 DNA 仅含有痕量的游离砷酸盐，没有可检测到的共价结合的砷酸盐。
