Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

’Accelerated evolution’ converts RNA enzyme to DNA enzyme in vitro

28.03.2006
Experiment offers fresh insights into the origins of life on Earth

This "evolutionary conversion" provides a modern-day snapshot of how life as we understand it may have first evolved out of the earliest primordial mix of RNA-like molecules-sometimes referred to as the "pre-RNA world"-into a more complex form of RNA-based life (or the "RNA world") and eventually to cellular life based on DNA and proteins. Nucleic acids are large complex molecules that store and convey genetic information, but can also function as enzymes.

While the transfer of sequence information between two different classes of nucleic acid-like molecules-between RNA and DNA, for example-is straightforward because it relies on the one-to-one correspondence of the double helix pairing, transferring catalytic function is significantly more difficult because function cannot be conveyed sequentially. The present study demonstrates that the "evolutionary conversion" of an RNA enzyme to a DNA enzyme with the same function is possible, however, through the acquisition of a few critical mutations.

The study was released in an advance online version of the journal Chemistry & Biology.

Scripps Research Professor Gerald F. Joyce, a member of the Skaggs Institute for Chemical Biology whose laboratory conducted the study, said, "During early life on earth both genetic information and catalytic function were thought to reside only in RNA. In our study, the evolutionary transition from an RNA to a DNA enzyme represents a genuine change, rather than a simple expansion, of the chemical basis for catalytic function. This means that similar evolutionary pathways may exist between other classes of nucleic acid-like molecules. These findings could help answer some fundamental questions concerning the basic structure of life and how it evolved over time."

As Francis Crick, the Nobel laureate who, along with James Watson uncovered the double helix structure of DNA, articulated in 1970, all known organisms operate according to the central dogma of molecular biology-that the transfer of sequential genetic information proceeds from nucleic acid to nucleic acid, and from nucleic acid to protein. But a far different situation exists with regard to the transfer of catalytic function, which does not occur sequentially in contemporary biology. The new study shows that catalytic function can be transmitted sequentially between two different nucleic acid-like molecules, suggesting how it might have been conveyed from pre-RNA molecules to RNA during the simpler pre-RNA world period.

There are several candidates for the initial pre-RNA molecule, all of which have the ability to form base-paired structures with themselves and with RNA. Cross-pairing would allow genetic information to be transferred from these pre-RNA molecules to RNA. The catalytic function of these early enzymes might have been transferred to a corresponding RNA enzyme following the acquisition of a few critical mutations, the study said, just as the evolutionary change of a ribozyme to a deoxyribozyme with the same or similar catalytic functions might also have occurred through random mutation and selection.

For the study, an RNA ribozyme was converted to a corresponding deoxyribozyme through in vitro evolution. The ribozyme was first prepared as a DNA molecule of the same RNA sequence but with no detectable catalytic activity. A large number of randomized variations of this DNA were prepared, and repeated cycles of in vitro evolution were carried out. The result was a deoxyribozyme with about the same level of catalytic activity as the original ribozyme.

"The use of in vitro evolution provides the means to convert a ribozyme to a corresponding deoxyribozyme rapidly," Joyce said. "In the laboratory these procedures allow us to carry out many generations of test tube evolution. The resulting molecules have interesting catalytic properties, they teach us something new about evolution, and they have potential application as therapeutic and diagnostic agents."

Keith McKeown | EurekAlert!
Further information:
http://www.scripps.edu

More articles from Life Sciences:

nachricht Water forms 'spine of hydration' around DNA, group finds
26.05.2017 | Cornell University

nachricht How herpesviruses win the footrace against the immune system
26.05.2017 | Helmholtz-Zentrum für Infektionsforschung

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Can the immune system be boosted against Staphylococcus aureus by delivery of messenger RNA?

Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.

Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....

Im Focus: A quantum walk of photons

Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.

The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....

Im Focus: Turmoil in sluggish electrons’ existence

An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.

We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...

Im Focus: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.

Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...

Im Focus: World's thinnest hologram paves path to new 3-D world

Nano-hologram paves way for integration of 3-D holography into everyday electronics

An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

AWK Aachen Machine Tool Colloquium 2017: Internet of Production for Agile Enterprises

23.05.2017 | Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

 
Latest News

How herpesviruses win the footrace against the immune system

26.05.2017 | Life Sciences

Water forms 'spine of hydration' around DNA, group finds

26.05.2017 | Life Sciences

First Juno science results supported by University of Leicester's Jupiter 'forecast'

26.05.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>