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NASA Confirms Discovery of Organism With Phosphorus-Free DNA

Posted by timothy on from the well-it's-not-that-shaggy dept.

GNUALMAFUERTE writes "As we mentioned before, NASA's Department of Astrobiology had an important announcement to make today. It looks like Gizmodo was right. You can watch the presentation online right now. It looks like the bacteria in question uses arsenic as a phosphorus replacement in its DNA."

8 of 380 comments (clear)

  1. Not Phosphorus-Free by Elder+Entropist · · Score: 5, Informative

    It replaces MOST phosphorus atoms with arsenic, but not all.

    1. Re:Not Phosphorus-Free by Mindcontrolled · · Score: 5, Informative

      From a biochemist's point of view, this is a huge substitution, as phosphate and arsenate compounds do usually not coexist well in organisms, hence the toxicity of arsenic. While "everything is made out of carbon", carbon is the rather boring compound that gives stuff its structure. High-energy-bonds, like formed by certain phosphate compounds, give stuff the energy to actually DO things. The virus defense theory is way off, btw - this bacterium evolved in a high-arsenic environment, so this is way more likely a way to cope with the chemical composition of its evolutionary niche.

      --
      Ubi solitudinem faciunt, pacem appellant.
    2. Re:Not Phosphorus-Free by ColdWetDog · · Score: 5, Informative

      It doesn't appear that they have got to the fun bits yet. Research is pretty much at the overview stage. They appear to have some crystallography data that suggests that the arsenic is bound to the DNA which suggests it's replacing the phosphorus backbone, but I don't see anything that shows the critter has replaced ATP (Adenosine TriPhosphate, the cellular power source) with Adenosine TriArsinate.

      Of course, one doesn't expect research to just dump everything out at once, there are many years of digging through this to sort it out.

      If arsenic is really powering the bacterium, then it's pretty impressive because the thing seems to grow at about 60% of maximum rate in a phosphate depleted source.

      --
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  2. real info by burris · · Score: 5, Informative

    According to this NYT article this is a normal earthly bacterium that, when placed in an environment full of arsenic, started swapping arsenic for phosphorus. It's not a totally new form of life unrelated to what we know.

  3. Gizmodo was not right by commisaro · · Score: 5, Informative
    The Gizmodo article, like most of the speculation, was largely overblown:

    NASA has discovered a completely new life form that doesn't share the biological building blocks of anything currently living in planet Earth, using arsenic to build its DNA, RNA, proteins, and cell membranes. This changes everything.

    That is not the case. The DNA is largely the same, except that phosphorous has been exchanged with Arsenic. Don't get me wrong, this is still a hugely interesting discovery, but it was implied during the pre-conference speculation that this was an entirely separate instance of abiogenesis, and that is simply not the case, unfortunately.

  4. Re:News flash: NASA discoveres there's life on ear by Defenestrar · · Score: 5, Informative

    My thoughts are as follows:

    THIS IS BLOODY AMAZING! followed by a little more tempered cogitation:

    Arsenate is a triprotic species just like phosphate, each has a valence of +5, and it's directly one period down on the table so available electron shells in ground state will appear very similar. However arsenic possesses filled d orbitals and is about 7% less electronegative than phosphorous - these factors, among others, tend to make arsenate a little more reactive than phosphate which would make it less stable as a backbone of DNA. So if the degree of replacement is as thorough as NASA claims (they said they cultured it with zero phosphorous present - so only trace impurities) the cell has either found a way to strengthen the backbone or has developed an amazing repair mechanism which can deal with frequent DNA damage.

    NASA has two summaries here and here.

    Astrobiology has an article here.

    And http://www.sciencemag.org/">Science will release a paper later today.

  5. MORONS POSTING ARTICLES WITH NO INFORMATION by DavidTC · · Score: 5, Informative

    See, this is why I hate slashdot.

    Instead of telling us 'Gizmodo was right', like we all read Gizmodo and keep constantly up to date about what's going on over there, how about TELLING US THE ACTUAL THING THAT HAPPENED.

    No, I shouldn't have to follow a link to figure it...there's supposed to be an 'article summary', which, you know, gives some hint as to what happened.

    Instead of just saying 'Oh, hey, these other people were right in their guess about a thing which i won't mention that they thought NASA would say.'. Well, woo-fucking-hoo. I'm sure we were all on the edge of our seat betting in the 'How correct is Gizmodo?' pool, and they just got a point! Wow! Who cares about actual news events, let's all sit there and count Gizmodo's points, or something.

    Timothy, you goddamn fucking moron. It's one thing when the article summary is misleading or just flat out incorrect, but slashdot has now managed to hit a new low where the article summary doesn't even exist.

    --
    If corporations are people, aren't stockholders guilty of slavery?
  6. Re:Neat, but... by c6gunner · · Score: 5, Informative

    It wasn't "political based bashing", it was a joke at the expense of David Icke and his weirdos. And it was damn funny, too.