Arsenic biochemistry
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Arseno-DNA refers to a hypothetical DNA analog in which arsenate partially or fully replaces phosphate present in the backbone. A 2010 paper in Science [1] reports that GFAJ-1, a proteobacterium from Mono Lake, is facultatively capable of incorporating arsenate into its DNA under conditions of phosphorus starvation. Other scientists are skeptical[2]; microbiologists Rosemary Redfield[3] and, separately, Athena Andreadis[4] have suggested the claims could potentially be based on errors in how the research studies were conducted. Several other chemists, including Nicholas Winograd, Keith O. Hodgson, Gerald Joyce, Ronald S. Oremland and John D. Sutherland have come out suggesting that the announcement is premature.[5]
Research
Felisa Wolfe-Simon of the US Geological Survey in Menlo Park, California, has been studying arsenic-utilizing bacteria named GFAJ-1, from Mono Lake. This bacterium shows signs of successfully incorporating arsenic into its structure, after an artificially-induced lack of phosphorus.[6][7] Arsenic is a toxic and carcinogenic substance for most forms of life because it readily replaces phosphorus in DNA and other important biomolecules. The GFAJ-1 bacterium have evidently evolved a mechanism to stabilize these substitutions and prevent or mitigate the cell damage that occurs in other organisms exposed to such high levels of arsenic. It is still unclear what that mechanism is.
Related discoveries
NASA announced at a press conference on 2 December 2010 the discovery of an organism that utilizes arsenic in its cellular structure.[8][9] Further cellular, DNA-RNA, and genome research will follow.[10] This would constitute the first discovery of a life form capable of replacing one of the "big six" elements in its makeup,[10] namely: carbon, hydrogen, oxygen, nitrogen, phosphorus and sulfur (or "CHONPS" for short).[11][12]
See also
References
- ^ Wolfe-Simon, Felisa; Blum, Jodi Switzer; Kulp, Thomas R.; Gordon, Shelley E.; Hoeft; Pett-Ridge, Jennifer; Stolz, John F.; Webb, Samuel M.; Weber, Peter K.; Davis, Paul C. W.; Anbar, Ariel D.; Oremland, Ronald S. (2 December 2010). "A Bacterium That Can Grow by Using Arsenic Instead of Phosphorus". Science. doi:10.1126/science.1197258. PMID 21127214. Retrieved 2010-12-06.
{{cite journal}}: Missing|author12=(help) - ^ Bortman, Henry (2 December 2010). "Arsenic-Eating Bacteria Opens New Possibilities for Alien Life". Space.com. Astrobiology Magazine (NASA). Retrieved 2010-12-08.
{{cite web}}: External link in|work= - ^ Redfield, Rosemary J. (4 December 2010). "Arsenic-associated bacteria (NASA's claims)". RR Research blog. Retrieved 2010-12-06.
{{cite web}}: External link in|work= - ^ Andreadis, Athena (3 December 2010). "Arsenic and Odd Lace". The Huffington Post. The Huffington Post. Retrieved 2010-12-08.
{{cite web}}: External link in|work= - ^ Arsenic Bacteria Breed Backlash: Controversy: Claim that microbe weaves arsenic into its DNA comes under fire December 8, 2010
- ^ Bortman, Henry (5 October 2009). "Searching for Alien Life, on Earth". Astrobiology Magazine (NASA). Retrieved 2010-12-02.
- ^ Harvey, Mike (4 March 2010). "Could the Mono Lake arsenic prove there is a shadow biosphere?". UK: The Times. Retrieved 2010-12-02.
- ^ Palmer, Jason (2 December 2010). "Arsenic-loving bacteria may help in hunt for alien life". BBC News. Retrieved 2010-12-02.
- ^ Kottke, Jason (29 November 2010). "NASA news conference participants". Kottke.org. Retrieved 2010-12-02.
- ^ a b Katsnelson, Alla (2 December 2010). "Arsenic-eating microbe may redefine chemistry of life". Nature News. doi:10.1038/news.2010.645. Retrieved 2010-12-02.
- ^ NASA.gov: "NASA-Funded Research Discovers Life Built With Toxic Chemical" 2 December 2010
- ^ NASA - Astrobiology Magazine: "Searching for Alien Life, on Earth" October 2009
External links
- Official NASA Presentation — Video (56:53) and additional information. — (3 December 2010)