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 Climate Impact Research in Hannover: Small Plants against Large Waves
17.08.2018 | Leibniz Universität Hannover

nachricht First transcription atlas of all wheat genes expands prospects for research and cultivation
17.08.2018 | Leibniz-Institut für Pflanzengenetik und Kulturpflanzenforschung

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Color effects from transparent 3D-printed nanostructures

New design tool automatically creates nanostructure 3D-print templates for user-given colors
Scientists present work at prestigious SIGGRAPH conference

Most of the objects we see are colored by pigments, but using pigments has disadvantages: such colors can fade, industrial pigments are often toxic, and...

Im Focus: Unraveling the nature of 'whistlers' from space in the lab

A new study sheds light on how ultralow frequency radio waves and plasmas interact

Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...

Im Focus: New interactive machine learning tool makes car designs more aerodynamic

Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.

When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...

Im Focus: Robots as 'pump attendants': TU Graz develops robot-controlled rapid charging system for e-vehicles

Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.

Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....

Im Focus: The “TRiC” to folding actin

Proteins must be folded correctly to fulfill their molecular functions in cells. Molecular assistants called chaperones help proteins exploit their inbuilt folding potential and reach the correct three-dimensional structure. Researchers at the Max Planck Institute of Biochemistry (MPIB) have demonstrated that actin, the most abundant protein in higher developed cells, does not have the inbuilt potential to fold and instead requires special assistance to fold into its active state. The chaperone TRiC uses a previously undescribed mechanism to perform actin folding. The study was recently published in the journal Cell.

Actin is the most abundant protein in highly developed cells and has diverse functions in processes like cell stabilization, cell division and muscle...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

LaserForum 2018 deals with 3D production of components

17.08.2018 | Event News

Within reach of the Universe

08.08.2018 | Event News

A journey through the history of microscopy – new exhibition opens at the MDC

27.07.2018 | Event News

 
Latest News

Smallest transistor worldwide switches current with a single atom in solid electrolyte

17.08.2018 | Physics and Astronomy

Robots as Tools and Partners in Rehabilitation

17.08.2018 | Information Technology

Climate Impact Research in Hannover: Small Plants against Large Waves

17.08.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>