Featured Research

from universities, journals, and other organizations

Mathematical Models Reveal 'Molten' And 'Glassy' States Of RNA

Date:
March 5, 2003
Source:
Ohio State University
Summary:
Mathematical models have given physicists a new look at DNA's chemical counterpart, RNA. The models -- showing that RNA behaves differently depending on the temperature of its environment -- may help biologists better understand how life evolved on Earth.

AUSTIN, Texas -- Mathematical models have given physicists a new look at DNA's chemical counterpart, RNA.

Related Articles


The models -- showing that RNA behaves differently depending on the temperature of its environment -- may help biologists better understand how life evolved on Earth.

The models suggest that high temperatures give twisted strands of RNA the flexibility to fold into many different shapes, while low temperatures cause it to collapse into a single shape.

Ralf Bundschuh, assistant professor of physics at Ohio State University, presented the results March 4 at the meeting of the American Physical Society in Austin, Texas.

RNA plays many different roles in a cell, such as the production of proteins that perform necessary functions, Bundschuh explained.

"People are probably more familiar with the genetic role of DNA, in which two strands of complementary base units bind to each other to create a double-helix structure. RNA behaves very much like a DNA molecule that has lost its complementary partner. In order for one strand of bases to form pairs, the strand must bend back onto itself -- it must fold," he said.

The structure of folded RNA resembles a severely twisted rubber band, with the shape of loops and branches determining its biological function.

Exactly how RNA folds into any particular shape is a mystery. Other researchers have tried to tackle the problem with computer simulations, by calculating the possible formations that result from a certain number of base units coming together. But simulating very realistic RNA molecules -- that is, very long RNA strands with many base units -- is difficult.

Bundschuh and Terence Hwa of the University of California, San Diego, examined the problem differently. They have developed the first mathematical theory for the possible states of an RNA molecule.

In the past, scientists only knew for sure that RNA could fold into a given configuration, depending on its chemical makeup. Instead, these mathematical models show that high temperatures cause RNA to enter a flexible state in which it can take on a variety of configurations. The flexible state is known as the "molten" state. When temperatures fall too low, the RNA enters a tangled, or "glassy," state.

"We know at high temperatures RNA is molten, and low temperatures, it is glassy. Somewhere in between, something has to happen to change its state from one to the other. We don't know what that is, yet," Bundschuh said.

Whether RNA forms a functional structure depends on the alignment of four base units -- adenine, guanine, cytosine and uracil -- a sequence of which resembles a strand of beads. When molten, the strand folds and unfolds with ease, and each base unit can connect with many different mates to form many possible overall shapes. In the glassy state, the strand "freezes" in a random pattern.

The results hold implications for the study of the related "protein folding problem." Researchers are working to understand the issues nature has to overcome to design new RNA sequences, because someday researchers may be able to design sequences themselves, for drugs or other disease therapies.

"One does not want to end up with a sequence that gets stuck in some random structure, or cannot decide which structure to fold into," Bundschuh said.

The work also has broader relevance for evolutionary biology, where experts have speculated that early life might have relied exclusively upon RNA.

"RNA could in fact be a stepping-stone to today's world of DNA. DNA cannot replicate without proteins, and proteins cannot be produced without RNA," Bundschuh said. "You could say we're characterizing what evolution is up against."

With five years' effort, Bundschuh and Hwa have only just begun to be able to model simple RNA activities that occur in less than a second, countless times every day.

"Now we can better appreciate what biology has to do to create a functional RNA molecule," he said.

Ohio State physics doctoral student Tsunglin Liu is working with Bundschuh to estimate how many base units would be required for computer simulations of more realistic RNA models, in order to observe the molten or glassy state. Liu has found that more than 8,000 units are necessary -- a computational task well beyond the reach of current studies, which are based on as few as 2,000 units.


Story Source:

The above story is based on materials provided by Ohio State University. Note: Materials may be edited for content and length.


Cite This Page:

Ohio State University. "Mathematical Models Reveal 'Molten' And 'Glassy' States Of RNA." ScienceDaily. ScienceDaily, 5 March 2003. <www.sciencedaily.com/releases/2003/03/030305081135.htm>.
Ohio State University. (2003, March 5). Mathematical Models Reveal 'Molten' And 'Glassy' States Of RNA. ScienceDaily. Retrieved November 27, 2014 from www.sciencedaily.com/releases/2003/03/030305081135.htm
Ohio State University. "Mathematical Models Reveal 'Molten' And 'Glassy' States Of RNA." ScienceDaily. www.sciencedaily.com/releases/2003/03/030305081135.htm (accessed November 27, 2014).

Share This


More From ScienceDaily



More Health & Medicine News

Thursday, November 27, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Ebola Leaves Orphans Alone in Sierra Leone

Ebola Leaves Orphans Alone in Sierra Leone

AFP (Nov. 27, 2014) — The Ebola epidemic sweeping Sierra Leone is having a profound effect on the country's children, many of whom have been left without any family members to support them. Duration: 01:02 Video provided by AFP
Powered by NewsLook.com
Experimental Ebola Vaccine Shows Promise In Human Trial

Experimental Ebola Vaccine Shows Promise In Human Trial

Newsy (Nov. 27, 2014) — A recent test of a prototype Ebola vaccine generated an immune response to the disease in subjects. Video provided by Newsy
Powered by NewsLook.com
Pet Dogs to Be Used in Anti-Ageing Trial

Pet Dogs to Be Used in Anti-Ageing Trial

Reuters - Innovations Video Online (Nov. 26, 2014) — Researchers in the United States are preparing to discover whether a drug commonly used in human organ transplants can extend the lifespan and health quality of pet dogs. Video provided by Reuters
Powered by NewsLook.com
Today's Prostheses Are More Capable Than Ever

Today's Prostheses Are More Capable Than Ever

Newsy (Nov. 26, 2014) — Advances in prosthetics are making replacement body parts stronger and more lifelike than they’ve ever been. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins