Triple-helix DNA?

[calbiterol]

No worries.

 

I rather enjoy a brief foray into the realm of fiction - it's a nice break from reality sometimes. One of the most interesting science-fiction related aspects of this is the infinite number of possibilities that an extraterrestrial lifeform could take. Something beyond our wildest imaginations would be, to put it simply, breathtakingly amazing.

[Conceptual]

The DNA double helix is held together via hydrogen bonding between base pairs. If one was to separate the double helix it will want to reform the double helix to minimize hydrogen bonding potential within the background hydrogen bonding potential of the water. A triple helix would contain too much residual hydrogen bonding potential. This would cause nonequilbrium for all the enzymes used for genetic expression. These enzymes would not want to approach and bind to the DNA. Instead the DNA would attract protein materials needed to help lower its hydrogen bonding potential.

 

Theoretically, one could modify the unpacking and transcription enzymes so that they are in equilibrium with this higher hydrogen bonding potential state of the DNA. But this would alter the hydrogen bonding gradient to the cellular membrane and cause the cellular gradient (positioning of materials) to shift, requiring new proteins to maintain the gradient. This new protein train may not be able to provide for the cellular diversity needed to express life.

[Kathryn]

Actually, 4 stranded DNA is VERY stable. It can only be formed by short sequences of guanine bases. Instead of assembling by Watson-Crick base pairing, it assembles via Hoosteen basepairing, so that a ring of 4 guanine bases comprises the base unit. This form of DNA can assemble in a varity of conformations, with both parallel and antiparallel strands, and is thought to play a role in sister chromatid alignment during recombination.

[bombus]

Triple or quadruple helices are unlikely to evolve as a standard as they are not generally needed as the having two works fine, and nature likes to keep things as simple as possible. That's why we only have two eyes to produce binocular vision (more than two is of no benefit) and two sexes (hermaphrodites are just two sexes in one creature) and ...err...other stuff. I'm sure you can think of other examples.

[Czech]

Ok, this post is going to confuse alot of you. And alot of you will not believe what I have to say. More then Double Helix DNA stands can and does exist. Ever sense I was an infant I have been in and out of countless hospitals and research facilities where they have ran countless tests to figure out how or why I have Quad Helix DNA. Alot of you are probably laughing and thinking i'm a moron or insane. But I have nothing to gain by making up such a complex lie. I would also like answers myself, sense I dont even know how this exist when the doctors and scientists wont tell me any information on the subject. Its like my own body is top secret information.

[Psycho]

Ok, this post is going to confuse alot of you. And alot of you will not believe what I have to say. More then Double Helix DNA stands can and does exist. Ever sense I was an infant I have been in and out of countless hospitals and research facilities where they have ran countless tests to figure out how or why I have Quad Helix DNA. Alot of you are probably laughing and thinking i'm a moron or insane. But I have nothing to gain by making up such a complex lie. I would also like answers myself, sense I dont even know how this exist when the doctors and scientists wont tell me any information on the subject. Its like my own body is top secret information.

You can't have that at you would be dead due to your DNA not being able to be transcribed, not to mention the whole problem with mitosis.

[David M.]

I really dont know much or for that matter anything about the Triple Helix but i have question's.

 

1. Can humans Naturally have a triple helix strand.

2. (only if there is a positive answer for 1) IF the triple helix stand can exist naturally in a human could it have any effect such as faster learning capabilities or advanced reflexes

3. Could the human body even have a artifical triple helix strand.

4 are all of these past questions impossible to determine at the moment.

By the way I am new and this is my first post and am only in the 8th grade:D

[Mr Skeptic]

Sorry, DNA only works in a double helix. Kind of how you can't stick two keys in a lock, the two DNA strands match each other. If you wanted a triple helix, you'd have to use a different molecule, and would change the vary basis of biology. You would die, unless you rewrote all your transcription factors to work with the triple helix.

[David M.]

So if we could geneticly change our double helix DNA strand to match that of a thrid strand and we bonded them could we even do that in the first place and then second could we keep doing that and i still dont get how our DNA gets transcribed.

[Mr Skeptic]

No, you wouldn't be able to use DNA. DNA forms double strands, and there would be no room for a third strand. Given that DNA forms the basis of most of your biology, it would be extremely hard to change.

[Imaginer1]

Triple helix? interesting but impossible. It only works in double strands, and if you made three strands imagine what you would get. .. aah!

[Mr Skeptic]

A triple helix is not impossible, but you would have to use something other than DNA. It wouldn't increase your strength, but it would add significant protection from mutation.

[David M.]

Okay let me get this staright.

A triple helix Dna strand can only exist if it can be transcribed and the hydrogen bonding is limited.

Then after that is done the whole body of the organisim would have to be redone to correctly work with the Triple helix strand.

Then even after that you would have to use something else besides Dna but can still be transcribed.

Then once all those have been done we would need differnt protiens to work with the new substance.

And after that what other substance could woud use besides Dna.

 

And then this all seems very confusing and do we even have the technology to remove replace and recreate substances into a living organism without it being in some sort of stasis?

 

And going back realy quicly to Czech.

Not a complex lie, you mispelled sinse ( it think thats right). Then if you were some sort of Top-Secret expirment like you say you would be traced edited and blocked from anything that could be spread, and if you were you would be in some sort of controlled area. Face it you made a lie just like my sister you did everything wrong:doh:. Start was wrong, Mispelled something giving you away, Typed or said something that contradicts exactly what you just said.

I could make a better lie. Ask me to make one and i will.

 

P.S. if i mispelled anything please tell me what it is. Also i have a post in homework section so could you help with that to.

[Mr Skeptic]

That is pretty much right. The whole body would not need to be changed, just most of the genetic code. Proteins not directly related to the DNA (which make up most of the mass of the body) could remain unchanged.

 

Another aspect of the triple stranded genetic material idea is that it would make medicine so much easier. The triple strand could have far lower mutation rate, possibly enough to make cancer unlikely. More importantly, it would give medicine a new weapon against disease -- anything that destroys DNA would kill all bacteria, and the DNA viruses, and the different structure would grant inherent immunity to retroviruses. That would leave RNA viruses as the only disease that would be untreatable, as well as any bacteria that gained resistance to DNA destroying substances.

[pioneer]

Triple stranded DNA could be designed. The simplest way would require a helical protein core with a greater affinity to hydrogen bond single strands of DNA than the DNA itself. If we look at a limited cross section, we would have sort of a circle of protein (simplified) with the hydrogen bonding every 120 degrees. Each of the three strands would bind to one of these sites. As we move axially the protein core helix would be wrapped with three binding DNA single helixes. This might be easier to do with RNA since it forms a single helix, easier, thereby not requiring any major tweaking.

[npts2020]

Here is an article written about how to produce triple helix DNA. http://www.sciam.com/article.cfm?id=triple-helix-designing-a-new-molecule

[Mr Skeptic]

Thanks, npts2020, that is a very interesting article. Especially for me, since I am studying genetics this semester.

[Moontanman]

Is triploidy what you guys are talking about? Most normal cells/organisms are dipliod. but triploidy does occur.

[pioneer]

Another way to make triple stranded DNA, is to design an inverse packing protein core. We design the core to hydrogen bond to the phosphate of DNA, so the bases are exposed on the surface of the triple helix complex for easy transcription.

[Polybacterium Cartellia]

Does it exist? Can it exist? Could it evolve naturally? Are there any inherent advantages to being a triple-helixed animal? How would a triple-helix lifeform differ from a double-helixer? What about multiple helixes? What effects would DNA of multiple helixes have on the creature that possessed it?

Yes, animals with triple-helix DNA are possible but they would need a different way of DNA replication than animals with double-helix DNA.

Edited April 7, 2016 by Polybacterium Cartellia

[Xalatan]

Btw, the triple helix structure does functionally exist in biology - collagen is triple helixed.

[Koni]

_{There is a Theoretical and Hypothetical real TRIPLE Helix DNA with three(3) nucleotide Bases which I have posted...}

_{This is the only alternative to the DOUBLE Helix DNA which has Hydrogen Bonds...}

 

[Area54]

On 15/10/2005 at 2:59 AM, calbiterol said:

I apologize if I have offended. There's nothing funny about finding out if there's truth in it, indeed, I do the same all the time and encourage it. Many foundations of modern science are based on the science fiction of the past.

 

The thing that made me laugh was what I must now relate as an extremely unlikely coincidence. There is currently a rather scientifically unfounded (read: pure fiction, with pseudoscience mixed in, probably deemed science fiction) TV show on Friday nights here in the US that includes in its impressively implausible resume the ability of an alien species (possibly a 4- or 5-dimensional one at that) to modify the human genome to a triple helix. The timing was such that I believed this to be where you got the idea; apparently, this is not the case. Had I looked at your location, I could have easily discovered this. The reference to spiral EM interference patters was the alien species's calling card: burned into almost all electronic devices (and arranged in some randomly chosen blood splatters on the floor) was a spiral-shaped interference pattern. So in reality, for you, there is absolutely no connection between the two.

 

Again, sorry, I didn't do the thorough background checking that I should have.

 

On 16/10/2005 at 0:47 AM, Xyph said:

Ah, oops, I should apologize for my defensiveness, then - I assumed (a bit too quickly, it turns out) that you were being critical of asking about things from fictional science, but since that's not the case, sorry about my reaction.

That's how forum discussions should be conducted. +1 to each of you.

(Hope that doesn't come across as patronising, it's just that I've seen situations like that rapidly deteriorate.)

[DrP]

On ‎01‎/‎09‎/‎2005 at 4:39 PM, Xyph said:

Ah, thanks. So, if life had evolved around a triple helix, would it externally be much the same as double helix life? Or is there no way to tell what differences there might be?

 

On ‎01‎/‎09‎/‎2005 at 4:54 PM, LucidDreamer said:

No way to tell. My guess is that it would be quite different because of the whole "butterfly effect."

Maybe the animals outwards appearance would look the same...  I say this due to evolution being driven by the needs of the animal to adapt and evolve to suit it's environment rather than being driven by it's chemistry. There are many cases of convergent evolution occurring like the Ichthyosaur and dolphin for example. If a swimming like animal had a triple helix it would still eventually grow into a dolphin/fish shape, because this is the best shape for swimming.  

 

 

[Koni]

^{IF there were a TRIPLE Helix DNA it were no differencies as to Organisms with a DOUBLE Helix DNA because they store INFORMATION in the same way!!!... The only difference is by the m-RNA's and t-RNA's... By a TRIPLE Helix with three (3/3) nucleobases you have: or (1) m-RNA=1/3 and t-RNA=2/3... or (2) m-RNA=2/3 and t-RNA=1/3 ...}