Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

DNA downloads alone

05.02.2002


Two million years ago life looked like this. Four billion years ago it was a different story.
© SPL


The information in DNA can be copied into new molecules without proteins’ help.

Chemists have reproduced the basic process of information transfer central to all life without the catalysts that facilitate it in living cells1.

They show that DNA alone can pass its message on to subsequent generations. Many researchers believe that DNA-like molecules acted thus to get life started about four billion years ago - before catalytic proteins existed to help DNA to replicate.



The experiment, carried out by David Lynn and co-workers at Emory University in Atlanta, Georgia, might create a new basis for the precise synthesis of useful polymer materials. It may even hasten the advent of synthetic biology: the creation of life from scratch.

History repeats itself

Synthetic self-replicating molecules have been made in the lab at least three times before. But in all these cases the replicating molecules were given a substantial helping hand.

Before, each molecule acted as a template on which its copy was constructed from two ready-made halves. In other words most of the information in the copy was present already in the fragments from which it was made. It was rather like reproducing the information in this sentence simply by pasting it together from two already-written halves.

In contrast, Lynn and colleagues paste each letter in place, one by one. They make, not a copy, but a complementary molecule, containing the same information but in a different code. It is rather like making a copy of one of these sentences but translated into French.

In the cell, DNA itself contains two such complementary molecules, each one a chain of molecular units, stuck together in the double helix. When DNA replicates before a cell divides, these complementary strands part and each acts as a template to guide the synthesis of a fresh strand.

Each DNA strand contains all the information needed to make a new strand. There are four different kinds of molecular unit, and the sequence of these along the strand determines the sequence of units assembled in the new strand. Enzymes drive this assembly process.

Stranded

Lynn’s group has found a way to do without the enzymes, so that a single strand of DNA can act as a template for the assembly of its complementary strand. Scientists have achieved this before, but imperfectly: only one of the four types of DNA unit acted as a template, and the complementary strand wasn’t always the same length as the template.

The Emory group uses a new trick to join the components together on a DNA template. The chemical links between successive units in the new strand aren’t like those in DNA itself. Instead they are amide linkages, like those that unite proteins’ molecular units, which are also chain-like molecules laden with information. This makes the assembly of the new strand more accurate.

Amide-linked DNA chains can help units of true DNA to join together. So the researchers hope to achieve the reverse process of templating DNA using amide-linked DNA. This might then enable the two kinds of molecule to support their mutual replication, allowing the possibility of molecular evolution and the appearance of life-like complexity.

References

  1. Li, X., Zhan, Z.-Y. J., Knipe, R. & Lynn, D. G. DNA-catalyzed polymerization. Journal of the American Chemical Society, 124, 746 - 747, (2002).


PHILIP BALL | © Nature News Service
Further information:
http://www.nature.com/nsu/020204/020204-2.html

More articles from Life Sciences:

nachricht Chains of nanogold – forged with atomic precision
23.09.2016 | Suomen Akatemia (Academy of Finland)

nachricht Self-assembled nanostructures hit their target
23.09.2016 | King Abdullah University of Science and Technology

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: OLED microdisplays in data glasses for improved human-machine interaction

The Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP has been developing various applications for OLED microdisplays based on organic semiconductors. By integrating the capabilities of an image sensor directly into the microdisplay, eye movements can be recorded by the smart glasses and utilized for guidance and control functions, as one example. The new design will be debuted at Augmented World Expo Europe (AWE) in Berlin at Booth B25, October 18th – 19th.

“Augmented-reality” and “wearables” have become terms we encounter almost daily. Both can make daily life a little simpler and provide valuable assistance for...

Im Focus: Artificial Intelligence Helps in the Discovery of New Materials

With the help of artificial intelligence, chemists from the University of Basel in Switzerland have computed the characteristics of about two million crystals made up of four chemical elements. The researchers were able to identify 90 previously unknown thermodynamically stable crystals that can be regarded as new materials. They report on their findings in the scientific journal Physical Review Letters.

Elpasolite is a glassy, transparent, shiny and soft mineral with a cubic crystal structure. First discovered in El Paso County (Colorado, USA), it can also be...

Im Focus: Complex hardmetal tools out of the 3D printer

For the first time, Fraunhofer IKTS shows additively manufactured hardmetal tools at WorldPM 2016 in Hamburg. Mechanical, chemical as well as a high heat resistance and extreme hardness are required from tools that are used in mechanical and automotive engineering or in plastics and building materials industry. Researchers at the Fraunhofer Institute for Ceramic Technologies and Systems IKTS in Dresden managed the production of complex hardmetal tools via 3D printing in a quality that are in no way inferior to conventionally produced high-performance tools.

Fraunhofer IKTS counts decades of proven expertise in the development of hardmetals. To date, reliable cutting, drilling, pressing and stamping tools made of...

Im Focus: Launch of New Industry Working Group for Process Control in Laser Material Processing

At AKL’16, the International Laser Technology Congress held in May this year, interest in the topic of process control was greater than expected. Appropriately, the event was also used to launch the Industry Working Group for Process Control in Laser Material Processing. The group provides a forum for representatives from industry and research to initiate pre-competitive projects and discuss issues such as standards, potential cost savings and feasibility.

In the age of industry 4.0, laser technology is firmly established within manufacturing. A wide variety of laser techniques – from USP ablation and additive...

Im Focus: New laser joining technologies at ‘K 2016’ trade fair

Every three years, the plastics industry gathers at K, the international trade fair for plastics and rubber in Düsseldorf. The Fraunhofer Institute for Laser Technology ILT will also be attending again and presenting many innovative technologies, such as for joining plastics and metals using ultrashort pulse lasers. From October 19 to 26, you can find the Fraunhofer ILT at the joint Fraunhofer booth SC01 in Hall 7.

K is the world’s largest trade fair for the plastics and rubber industry. As in previous years, the organizers are expecting 3,000 exhibitors and more than...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Experts from industry and academia discuss the future mobile telecommunications standard 5G

23.09.2016 | Event News

ICPE in Graz for the seventh time

20.09.2016 | Event News

Using mathematical models to understand our brain

16.09.2016 | Event News

 
Latest News

Chains of nanogold – forged with atomic precision

23.09.2016 | Life Sciences

New leukemia treatment offers hope

23.09.2016 | Health and Medicine

Self-assembled nanostructures hit their target

23.09.2016 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>