Researchers Design DNA With New Shapes and Structures

Jason Koebler writes: The shape of DNA is a double helix, right? That's what we are taught. Well, now the answer is "not always." Researchers at the Massachusetts Institute of Technology have discovered how to program DNA to be shaped like a bowl, or a spiral, or a ring, or other shapes that aren't found in nature.

It's the latest in a string of discoveries about the underlying structure of life and the building blocks by which it's made. Recently, scientists created new nucleotides that do not exist in nature and inserted them into a living organism. And now, this: DNA can look like just about anything and can be assembled into many shapes.

Comments

Multipass

[RivenAleem]

Me fifth element - supreme being. Me protect you.

Re:Multipass

[ArcadeMan]

Autowash.

Steps to molecular machines?

[babymac]

The next step should be to figure out how to create DNA "tools" to help assemble molecular scale machines!

Humor

[justsomecomputerguy]

What do you make of it Johnny?! Well, you can make a hat, a broach, a pterodacty!....

This should be a given..

[rahvin112]

This should be a given, this is how the body makes proteins. The "recipe" is stored in the DNA, the transcriber runs along the DNA making a copy and then it folds into the protein when the copy is complete. A small mistake in the transcription and it doesn't fold into the right protein or doesn't fold at all. This is why protein research is so hard right now, they don't fully understand what governs how the proteins fold.

This research may give them a leg up on understanding that, very cool that they figured out some of the rules.

Re:This should be a given..

[kebes]

The base-pair sequence of DNA determines its biological function. As you say, this sequence determines what kinds of proteins get made, including their exact shape (and more broadly how they behave).

But TFA is talking about the conformation (shape) of the DNA strand itself, not the protein structures that the DNA strand is used to make.

In living organisms, the long DNA molecule always forms a double-helix, irrespective of the base-pair sequence within the DNA. DNA double helices do actually twist and wrap into larger-scale structures: specifically by wrapping around histones, and then twisting into larger helices that eventually form chromosomes. There are hints that the DNA sequence itself is actually important in controlling how this twisting/packing happens (with ongoing research about how (innapropriately-named) "junk DNA" plays a crucial role). However, despite this influence between sequence and super-structure, DNA strands essentially are just forming double-helices at the lowest level: i.e. two complementary DNA strands are pairing up to make a really-long double-helix.

What TFA is talking about is a field called "DNA nanotechnology", where researchers synthesize non-natural DNA sequences. If cleverly designed, these sequences will, when they do their usual base-pairing, form a structure more complex than the traditional "really-long double-helix". The structures that are designed do not occur naturally. People have created some really complex structures, made entirely using DNA. Again, these are structures made out of DNA (not structures that DNA generates). You can see some examples by searching for "DNA origami". E.g. one of the famous structures was to create a nano-sized smiley face; others have 3D geometric shapes, nano-boxes and bottles, gear-like constructs, and all kinds of other things.

The 'trick' is to violate the assumptions of DNA base-pairing that occur in nature. In living cells, DNA sequences are created as two long complementary strands, which pair up with each other. The idea in DNA nanotechnology is to create an assortment of strands. None of the strands are perfectly complementary to each other, but 'sub-regions' of some strands are complementary to 'sub-regions' on other strands. As they start pairing-up with each other, this creates cross-connections between all the various strands. The end result (if your design is done correctly) is that the strands spontaneously form a ver well-defined 3D structure, with nanoscale precision. The advantage of this "self-assembly" is that you get billions of copies of the intended structure forming spontaneously and rapidly. Very cool stuff.

This kind of thing has been ongoing since 2006 at least. TFA erroneously implies that this most recent publication invented the field. Actually, this most recent publication is some nice work about how the design process can be made more robust (and software-automated). So, it's a fine paper, but certainly not the first demonstration of artificial 3D DNA nano-objects.

wrong

[WindBourne]

It is still double helix. It is the tertiary structure that is being played with, not the helix. Without the double helix, it would be to easy to have errors. In addition, nature enzymes are designed for double helix and the zipper effect.

Re:wrong

[quantumghost]

Double stranded DNA is more resistant to errors, but not immune. At the most basic level, the double helix provides complementary redundancy, the problem then becomes: which strand has the error and which is the true strand. http://en.wikipedia.org/wiki/D...

Cosmic DNA?

[handy_vandal]

Space dust may store information as a double helix.

A new computer simulation shows that dust immersed in ionized gas (i.e., dusty plasmas) can organize itself into double helixes. The simulations suggested that under conditions commonly found in space, the dust particles first form a cylindrical structure that sometimes evolved into helical structures. Along some spirals, the radius of the helix was seen to change abruptly from one value to another and then back again, providing a mechanism for storing information in terms of the length and radius of a section of a spiral.

Hessdalen light