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Thread: Loooking for updated info on GFAJ-1

  1. #1 Loooking for updated info on GFAJ-1 
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    I am looking for updated articles/papers on GFAJ-1.
    I am out of academia so I do not have the privilege of unlimited access to papers.
    If their DNA backbone consists of As instead of P then Im assuming they have to start everything from scratch? All the enzymes, methods that are involved in extraction/cloning have to be developed?
    What are some similarities/differences with DNA w/As backbone?
    If any of you have any updated things to read, that would be much appreciated.
    Thank you in advance!


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  3. #2  
    Forum Freshman Mark Ian's Avatar
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    I would also appreciate more a detailed form or kind of document on GFAJ bacterium and related documents.


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  4. #3  
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    It would appear that these bacteria are completely dependent upon phosphorus for survival. It would also appear that phosphorus was present as a contaminant in the growth media - at concentrations two orders of magnitude higher than is found in some natural environments where bacteria grow just fine. It would also appear that the amount of arsenate in each bacterial genome equates to around just 400 atoms of arsenic (by one estiimate) - and it's not even clear if that arsenate is nothing more than a contaminant.

    Arsenic-associated bacteria (NASA's claims) on Rosie Redfield's RRRESEARCH blog

    Arsenate-based DNA: a big idea with big holes by Alex Bradley on "We, Beasties".

    DNA, Phosphorus, and Arsenic on Larry Moran's "Sandwalk" blog.

    This Paper Should Not Have Been Published by Carl Zimmer on "Slate".

    Compare those articles with this NASA release: NASA-Funded Research Discovers Life Built With Toxic Chemical and this YouTube video

    Thunderf00t (an acolyte of AronRa) also has a video (I've yet to watch it though): Did NASA really find New Life??

    Sorry to be so negative on this story. I would also like to point out that maybe I've just swallowed all the bad hype wholesale.


    Since arsenic is toxic to life I really don't find it all surprising that we can find some of it bound to biological molecules of importance when an organism is exposed to it.
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  5. #4  
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    Hey,

    If you need any papers just let me know and I will send them to you.

    Tridimity :wink:
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  6. #5  
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    The paper I read didn't show any direct evidence of arsenate being incorporated into the back bone, only evidence that implied it.

    As far as enzymology, no. Aresenate is very similar to phosphate in size and polarizibility. It is the reason why arsenate is a poison - the similarity allows it to act as an uncoupler, binding to ADP in phosphorous' place, forming a useless molecule. The amount of change necessary for the effective use of arsenate would be huge, not in terms of greatly altering enzyme specificity, but rather in the number of enzymes that would have to be changed. Further, I've read that arsenate forms far less stable bonds, so that presents a whole new level of challenge to a bacteria using it in place of phosphate. I'm honestly starting to doubt the findings of the original article.

    Also, just for people who don't know, arsenite is the very poisonous form of arsenic. It is a much softer base, making it act like other soft heavy metals(lead, mercury). It binds to thioesters which cause massive widespread problems, including inhibition of oxidative phosphorilation.
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  7. #6  
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    Thank you very much for your valuable input.
    First link in Zwirko's reply pretty much answered my questions on this topic. I'm actually bit surprised to read how poorly designed this study was by NASA.
    And thank you tridimity, I may have to take up on your kind offer one day
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  9. #8  
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    Thank you very much Erebus
    I never knew about this pdfcast site, it looks like its got lots of interesting different stuff!
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