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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."

47 of 380 comments (clear)

  1. First post (hopefully) by Anonymous Coward · · Score: 5, Funny

    It's life Jim, but not as we know it.

  2. Neat, but... by mikaelwbergene · · Score: 5, Insightful

    This is neat and clearly an important discovery and all, but I'd be lying if I said I wasn't a little bit disappointed.

    1. Re:Neat, but... by ultranova · · Score: 4, Funny

      This is neat and clearly an important discovery and all, but I'd be lying if I said I wasn't a little bit disappointed.

      Cheer up, the broadcast is still going. They're just using the phosphorus-free DNA as a red herring to make the final part more shocking. You know, the last minute where they reveal Bush tied to a chair, take a good grip on his nose, and pull off the human mask to reveal a reptilian overlord beneath.

      --

      Forget magic. Any technology distinguishable from divine power is insufficiently advanced.

    2. Re:Neat, but... by albeit+unknown · · Score: 5, Funny

      This is neat and clearly an important discovery and all, but I'd be lying if I said I wasn't a little bit disappointed.

      Cheer up, the broadcast is still going. They're just using the phosphorus-free DNA as a red herring to make the final part more shocking. You know, the last minute where they reveal Bush tied to a chair, take a good grip on his nose, and pull off the human mask to reveal a reptilian overlord beneath.

      and he would have gotten away with it if it weren't for you meddling kids!

    3. Re:Neat, but... by Bob9113 · · Score: 5, Funny

      where they reveal Bush tied to a chair, take a good grip on his nose, and pull off the human mask to reveal a reptilian overlord beneath.

      Don't they have to rip the Obama mask off first to reveal Bush underneath?

      --
      Stop-Prism.org: Opt Out of Surveillance
    4. Re:Neat, but... by JustOK · · Score: 5, Funny

      it's Presidents all the way down.

      --
      rewriting history since 2109
    5. Re:Neat, but... by Obfuscant · · Score: 4, Insightful
      You know, it gets a bit old and stale, and quite a bit tiring, for this gratuitous political-based bashing, here in a blog intended for "news that matters" for "nerds".

      It's depressing to come to a discussion about some new discovery in science just to find a long and boring thread with Bush (or Obama) bashing as the goal.

    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.

  3. 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 SleazyRidr · · Score: 3, Insightful

      But it's still a carbon-based life-form right?

      (Not that I'm trying to diminish this, I think it's awesome. Just trying to get my facts straight.)

      --
      Is 1563649 a prime number?
    2. Re:Not Phosphorus-Free by arth1 · · Score: 5, Funny

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

      Correct. It replaces the rest with old lace.

    3. Re:Not Phosphorus-Free by jfengel · · Score: 5, Insightful

      That's correct. The carbons (and hydrogens and oxygens and nitrogens) are all where they should be. It's only the phosphorus that has been swapped out, for arsenic (right below it on the periodic table).

      In fact arsenic is toxic to you precisely because it takes the place of phosphorus so easily, without doing all of the jobs. Except for this little guy, who manages to work around the differences and survive nearly phosphorus-free.

    4. Re:Not Phosphorus-Free by Mindcontrolled · · Score: 3, Informative

      Well, as much as anything is carbon based, yes. We are carbon-hydrogen-oxygen-nitrogen-sulfur-phosphorus-based, this one is carbon-hydrogen-oxygen-nitrogen-sulfur-phosphorus/arsenic-based. That still makes for a major metabolic difference, but it is still biologically related to us. Same tree of life. Still way cool, though.

      --
      Ubi solitudinem faciunt, pacem appellant.
    5. Re:Not Phosphorus-Free by yincrash · · Score: 4, Interesting

      To be very clear, Felisa (the primary paper author) stated during the Q&A that all they know for sure is that there is not enough phosphorus in the bacteria for it's biochemical processes and the only reasonable conclusion is that arsenic is taking it's place. Not enough analysis to know percentages of what is using what.

    6. Re:Not Phosphorus-Free by pi_is_after_you · · Score: 4, Insightful

      That's what surprises me. If it's on the same column, it will have roughly the same properties and fit in the same reactions, but have vastly different reaction rates and affinities. So, does this thing replace phosphorous in DNA/RNA, ATP, and phospholipids? What about phosphorylation? /p.s. This is my first post to slashdot in approximately 4 years

    7. Re:Not Phosphorus-Free by sam_handelman · · Score: 5, Insightful

      Yes, it is still carbon-based.

        In fact, this appears to be a biochemically-interesting but seriously overhyped discovery.

        AFAICT, this organism still uses the same genetic code, the same nucleotide bases, the same ribose sugars, the same everything - only this organism performs a chemical modification of the phosphate backbone, substituting in arsenic. This is only moderately different from the chemical modifications that we make to our own DNA, RNA and proteins (methylation, for example.)

        That's not a particularly shocking substitution, from a chemical standpoint, and doesn't really say anything about the viability of an organism with an actually *alien* biochemistry. Now, if you look at the periodic table, you'll see that Arsenic is right below Phosphorous - so in a sense, this is a bit like the much more exciting Carbon -> Silicon change which might get you talking rocks on lava worlds breathing vaporized sand and other badass shit. But it's only a tiny bit similar to that, because the role that Phosphorous plays in biology is much different than that of Carbon. Carbon is what everything is made-out-of, Phosphorous is stuck onto the ends of things in order to provide high-energy bonds which can be exploited as an energy currency.

        I would bet that this organism does this as a defense against viruses - which, generally speaking, will not have arsenic-DNA or arsenic-RNA, and so would not be able to infect this organism.

      --
      The good and new comes from no quarter where it is looked for, and is always something different from what is expected.
    8. 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.
    9. Re:Not Phosphorus-Free by MichaelSmith · · Score: 3, Interesting

      In fact arsenic is toxic to you precisely because it takes the place of phosphorus so easily, without doing all of the jobs. Except for this little guy, who manages to work around the differences and survive nearly phosphorus-free.

      Makes me wonder if this is an organism which has adapted to tolerate the damage from arsenic which would kill us.

      --
      http://michaelsmith.id.au
    10. 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.

      --
      Faster! Faster! Faster would be better!
    11. Re:Not Phosphorus-Free by Defenestrar · · Score: 4, Interesting

      Sounds good except for the fact that you're forgetting that arsenate is more reactive than phosphate which means the arsenate based backbone of DNA should be constantly getting ripped to shreds. Either this bacteria has found a way to protect the backbone or it has a hyper effective repair mechanism. Either would be very worth learning about. (Immortality anyone)?

    12. Re:Not Phosphorus-Free by frank_adrian314159 · · Score: 4, Funny

      Same tree of life.

      Oh, you wacky evolutionists! Everyone knows that God doesn't mention this lifeform in Genesis, so it must be either (a) an analytical error, (b) a test of faith, or (c) a trick by Satan meant to deceive us. No proof of evolution here - move along...

      --
      That is all.
    13. Re:Not Phosphorus-Free by Mindcontrolled · · Score: 5, Funny

      Man, don't you see? They got poison for holding together their DNA. That's not just a trick of Satan, that's Satan's own DNA! The Enemy is growing his spawn right there in California (not that anyone would be surprised by that). The end is near! Repent! Bible-based science - it works, bitches!

      --
      Ubi solitudinem faciunt, pacem appellant.
    14. Re:Not Phosphorus-Free by sconeu · · Score: 4, Funny

      Same tree of life.

      So this is the microorganism that turns us into Pak protectors?

      --
      General Relativity: Space-time tells matter where to go; Matter tells space-time what shape to be.
    15. Re:Not Phosphorus-Free by robotkid · · Score: 4, Informative

      Makes me wonder if this is an organism which has adapted to tolerate the damage from arsenic which would kill us.

      This organism, almost certainly not. Most of these extremophiles are miserably slow growers (the doubling time was ~2 days vs 20 minutes for E. coli), so unless there's a niche somewhere in your body that allows the extremophile's adaptations to be a major advantage, it would never gain a foothold in your body as the many strains of bacteria we symbiotically live with will outcompete it for resources.

      But as to the more general question of whether any dangerous extremophiles exist out there - this is a recurring topic of speculation (over beer) amongst those that work with pathogenic microbes. Consensus seems to be that it's not impossible that an extremophile such as an archaea, or, in this case, a protobacteria could potentially be an opportunistic pathogen as well, but we haven't found one yet so it's probably not a common occurrence. The organism in this press release is a distant, distant cousin of helicobacter Pylori, an acid-loving bacteria which causes ulcers and is linked with gastric cancer, so it's not insane to think it could happen. Just unlikely.

  4. Not phosphorus free, not just DNA. by Confusedent · · Score: 4, Informative

    It wasn't phosphorus free, in fact they hadn't confirmed how much of the phosphorus had been substituted with arsenic, but they did mentioned it was not 100%. They also mentioned it was more than just DNA (ATP was also mentioned, although they implied more).

  5. 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.

    1. Re:real info by blair1q · · Score: 4, Informative

      But it sort of is.

      We've always ignored the chances of life on extraterrestrial bodies with significant levels of arsenic on the empirically founded theory that arsenic doesn't work in place of phosporus in living systems.

      So while this is a lifeform we already knew about, it's a different form of life from what we understood.

      The question remains, is it possible for DNA to have evolved in an environment rich in arsenic, or would it have had to evolve in an arsenic-free environment, and just happen to have enough integrity once it's formed to tolerate the replacement of phosphorus atoms with arsenic atoms?

  6. Obligatory question by JamesP · · Score: 5, Funny

    How I am supposed to poison the darn thing now??!?!

    --
    how long until /. fixes commenting on Chrome?
    1. Re:Obligatory question by PhilHibbs · · Score: 4, Funny

      Shampoo?

  7. 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.

  8. Re:Announce an Announcement... by arth1 · · Score: 5, Insightful

    NASA has really started to irritate me, with their latest few announcements. Rather than just issuing the data and having a little show about its implications in NASA TV, they first make an announcement that they will make an announcement, then for a few weeks there is rampant speculation (even though it's entirely probable that the data is ready) and finally they make their announcement in a media-circus style event.

    They probably hired a PR manager who used to work at Apple.

  9. Arsenic and Old GFA-J1 by digitaldc · · Score: 5, Insightful

    The discovery of this microorganism that can use arsenic to build its cellular components may indicate that life can form in the absence of large amounts of available phosphorus, thus increasing the probability of finding life elsewhere in the universe. The find gives weight to the long-standing idea that life on other planets may have a radically different chemical makeup and may help in hunt for alien life.

    The more we think we know about, the greater the unknown... -Neil Peart

    --
    He who knows best knows how little he knows. - Thomas Jefferson
  10. Re:Hardly deserves the "New Life" headline.. by andrewd18 · · Score: 3, Informative

    This wasn't "bred" or modified by the scientists from an existing bacterium, it was occurring naturally in Mono Lake and was transported to the lab for concentrated study. That was the second-to-last question answered in the NASA TV broadcast.

  11. 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.

  12. Re:Why all the fuss? by Amouth · · Score: 4, Insightful

    because this confirms many unproven ideas that not all "life" is in the same form as we are a custom too - other than this.. all life that we knew before now on earth used the same base DNA structure..

    basically they have found life.. not as we know it.. and means that some of our methods for proving there isn't life some place might be flawed.

    --
    '...if only "Jumping to a Conclusion" was an event in the Olympics.'
  13. I just read the Science paper by Anonymous Coward · · Score: 3, Informative

    What they did was take samples of bacteria from the mud, and placed them in three conditions. In one condition they kept raising the cells in normal, phosphorous containing substrate, removing a small portion to another phosphorous containing substrate, and repeating for generations. In another they put the cells on a substrate lacking phosphorous or arsenic, and removed a small portion to another empty substrate, and so on. Finally, they put some on a substrate containing phosphorous and arsenic, and kept pulling out small proportions an introducing them to plates higher and higher in arsenic. The serial dilutions eventually decreased the amount of phosphorous to amounts too small to account for the needs of bacteria. Cells grew on both phosphorous and arsenic plates, but they grew better in phosphorous. The arsenic cells had some weird vacuoules which might be helping to stabilize the arsenic based compounds.

    They don't know if cells in the wild have this ability or if they evolved the ability over the course of serial dilutions. A simple mass spec can tell that the ones in the wild are not mostly arsenic based though.

  14. 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?
  15. Re:News flash: NASA discoveres there's life on ear by mcgrew · · Score: 3, Interesting

    This link may help. If not (it is, after all, a link to the chemistry department of a university), this, this, or this may.

    And yes, since it has to do with DNA it is indeed porn on acid. Or maybe acid on porn.

    --
    Free Martian Whores!
  16. Re:News flash: NASA discoveres there's life on ear by gilleain · · Score: 3, Interesting

    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

    Hmmm. Maybe it methylates the DNA more? Or the histones are different. I guess - as you say - more repair enzymes is quite likely, since that just requires some promoter mutations.

    The interesting question for me is whether any of the mechanisms are different for this organisms enzymes. For the last few months I've been sitting on the next desk to the maintainer of a database of biochemical mechanisms (MACiE - hi gemma, assuming you read slashdot, and happy birthday...) so maybe that's why it occurs to me. Many enzymes use ATP/NAD/other phosphate cofactors to make stuff, so if AsO4 has a slightly different chemistry, I wonder if different sidechains are used. Or, as I say, some completely different mechanisms (or pathways?).

  17. Re:First life form! by jitterman · · Score: 5, Funny

    I wonder if they found the Old Lace component yet.

    --
    For conscience is the wound, and there's naught to staunch it
  18. Re:News flash: NASA discoveres there's life on ear by patjhal · · Score: 4, Interesting

    Yes. This is pretty significant. I wonder if there are any viruses that can effect them. Read about the Hershey–Chase experiment if you want to see how significant this is https://secure.wikimedia.org/wikipedia/en/wiki/Hershey%E2%80%93Chase_experiment

  19. Re:News flash: NASA discoveres there's life on ear by somersault · · Score: 5, Insightful

    Similar things were thought about phosphate groups. Unfortunately, we were wrong.

    Unfortunate? I don't think it's unfortunate at all. It's things like this that make us question our "universal truths" that makes science so interesting and worthwhile.

    If we already knew everything there would be no need for science. We may "know a lot", but there's not a shortage of new things to learn.

    I don't necessarily think you're wrong about the carbon and hydrogen thing - I've only really studied a little physics and chemistry, no biology. But I do think you need to be more open to being wrong - and to see it as an opportunity to grow rather than as a slap in the face.

    --
    which is totally what she said
  20. Re:First by digitalsushi · · Score: 4, Funny

    I accept your apology.

    --
    slashdot: where everyone yells sarcastic metaphors to themselves to understand the issue
  21. Link to Video of Press conference by Danathar · · Score: 3, Informative

    I captured and converted it to mp4 format for anybody that wants to view it.

    http://www.wuala.com/danathar/public

    file is nasa.mp4 (it's the only one on that page)

  22. Re:First by mcgrew · · Score: 4, Informative

    Actually, they DID discover a new life form. They didn't actually coax an existing bacteria to "use phosphorus". Instead, they discovered an existing organism that can use arsenic in its DNA and RNA rather than the phorphorus other life on earth uses.

    Carbon, hydrogen, nitrogen, oxygen, phosphorus and sulfur are the six basic building blocks of all known forms of life on Earth. Phosphorus is part of the chemical backbone of DNA and RNA, the structures that carry genetic instructions for life, and is considered an essential element for all living cells.

    Phosphorus is a central component of the energy-carrying molecule in all cells (adenosine triphosphate) and also the phospholipids that form all cell membranes. Arsenic, which is chemically similar to phosphorus, is poisonous for most life on Earth. Arsenic disrupts metabolic pathways because chemically it behaves similarly to phosphate.

    The newly discovered microbe, strain GFAJ-1, is a member of a common group of bacteria, the Gammaproteobacteria. In the laboratory, the researchers successfully grew microbes from the lake on a diet that was very lean on phosphorus, but included generous helpings of arsenic. When researchers removed the phosphorus and replaced it with arsenic the microbes continued to grow. Subsequent analyses indicated that the arsenic was being used to produce the building blocks of new GFAJ-1 cells.

    The key issue the researchers investigated was when the microbe was grown on arsenic did the arsenic actually became incorporated into the organisms' vital biochemical machinery, such as DNA, proteins and the cell membranes. A variety of sophisticated laboratory techniques was used to determine where the arsenic was incorporated.

    --
    Free Martian Whores!
  23. Re:News flash: NASA discoveres there's life on ear by Defenestrar · · Score: 3, Interesting

    Thanks for filling in the blanks. There's some things that I deal with so often that I forget I can sound a little weird when I get excited about science and open my mouth - phosphate is one of them.

    But yeah - the short story is that phosphate (and arsenate) have three spots to kick hydrogen on or off with - and the number of hydrogens that hang out on a phosphate ion is very much related to the pH.

    The long story (for anyone who cares) is that each of those hydrogens has a different equilibrium constant (pKa) at which it will pop off. H3PO4 is phosphoric acid but if you increase the amount of OH- in solution (or reduce the amount of H+) the first of those hydrogens will hook up with the OH- to make water which leaves H2PO4-. So the next hydrogen to take a hike will leave the phosphate at HPO4- - which means it's harder to leave and has a different pH (which is a fancy way of talking about the levels of H+ and OH- in water) it will hit equilibrium with. So on and so forth for each of the four phosphate species (0, -1, -2, -3 charge).

    The really long version throws out concentration of the different species of phosphate and talks about activities, taking into account that the activity coefficient is affected by the square of the ion's charge... [We interrupt this chemistry lesson for the sake of sanity]

    Strange - I forgot what I was talking about - but back to your question: yeah - DNA is both sex and acid

  24. Holy crap! by DG · · Score: 3, Interesting

    What if this microbe isn't "new" - what if it is old?

    As in - what if life on Terra initially evolved based around an arsenic atom, and then later evolved to use the much better and more stable phosphorus?

    DG

    --
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