Featured Research

from universities, journals, and other organizations

22nd Amino Acid Synthesized And Added To Genetic Code Of E. Coli Bacteria

Date:
September 20, 2004
Source:
Ohio State University
Summary:
Two years ago, Ohio State University researchers surprised the scientific community by announcing their discovery of a 22nd genetically encoded amino acid. Now they have capped that discovery with news that they have successfully synthesized the amino acid itself – L-pyrrolysine – and shown that bacteria can incorporate it into new proteins – the biological components which do most of the work in cells.

COLUMBUS, Ohio – Two years ago, Ohio State University researchers surprised the scientific community by announcing their discovery of a 22nd genetically encoded amino acid.

Now they have capped that discovery with news that they have successfully synthesized the amino acid itself – L-pyrrolysine – and shown that bacteria can incorporate it into new proteins – the biological components which do most of the work in cells.

The importance of their work is the explanation of exactly how the 22nd amino acid is incorporated into proteins inside living cells. The genetic instructions to put pyrrolysine into proteins follows a traditional path that many scientists had not predicted.

For decades following the discovery of the structure of DNA, the dogma was that the genes in the DNA were decoded to produce proteins built from only 20 “canonical” amino acids.

But in 1986, researchers discovered that a 21st amino acid – selenocysteine – was incorporated into certain proteins. What separated selenocysteine from the other previously identified amino acids was the fact that it was inserted into protein by a very different path.

Each of the canonical amino acids uses a specialized translator protein to decode genetic information as that amino acid. But selenocysteine lacked its own translator protein and is put into the protein through a more circuitous route.

That left open the question of whether future amino acids would follow the traditional path of the first 20 amino acids or the unusual route taken by 21st.

In the end, tradition won out.

The results are described in two papers published in scientific journals this month. The first appeared in the British journal Nature and the second in the journal Chemistry and Biology.

“In recent years, researchers learned to artificially modify a set of translator enzymes so that new amino acids can be genetically programmed in cells to produce novel proteins for biotechnology,” explained Joe Krzycki, a professor of microbiology.

“Now it looks like nature has been doing the same kinds of experiments all along and has produced a never-before-seen translator protein for pyrrolysine.”

Following their joint discovery of L-pyrrolysine, Krzycki’s colleague Michael Chan, an associate professor of biochemistry and chemistry at Ohio State, began the laborious process of synthesizing the actual chemical compound. After nearly a year’s worth of work and a 10-step process, Chan’s research group provided Kyzycki’s group with a small amount of this chemically synthesized pyrrolysine.

“The sample that Michael’s team produced was exactly what the chemical structure that we’d predicted said it should be,” Krzycki said.

The final step was to see if the translator enzyme for L-pyrrolysine would function normally within a living cell. To test that, they inserted the enzyme into Escherichia coli bacteria. Researchers use E. coli as an easy test for some basic biological functions.

Once inside the microbe, the enzyme was able to change the genetic coding in the organism so that it now included L-pyrrolysine as well as the other 21 amino acids.

“What this set of experiments has shown us is that it is probably a little easier than we might have thought it would be to change the genetic code in an organism like E. coli,” Krzycki said. “It gives us some new insight into how the genetic code evolved, that’s the take-home message.”

Chan called the project itself “a great example of how researchers in chemistry and biology can come together to solve some important fundamental scientific questions.”

Future research may suggest new ways to make artificial proteins with unusual chemical properties for use in medicine or industry, Krzycki said.

The research was supported by the National Science Foundation, the National Institutes of Health, the Department of Energy and the Alfred P. Sloan Foundation.

Along with Chan and Krzycki, Bing Hao, Gang Zhao, Patrick Kang, Jitesh Soares, Tsuneo Ferguson, Judith Gallucci, Sherry Blight, Ross Larue, Anirban Mahapatra, David Longstaff, Edward Chang, and Kari Green-Church all worked on the project.


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. "22nd Amino Acid Synthesized And Added To Genetic Code Of E. Coli Bacteria." ScienceDaily. ScienceDaily, 20 September 2004. <www.sciencedaily.com/releases/2004/09/040920070150.htm>.
Ohio State University. (2004, September 20). 22nd Amino Acid Synthesized And Added To Genetic Code Of E. Coli Bacteria. ScienceDaily. Retrieved October 22, 2014 from www.sciencedaily.com/releases/2004/09/040920070150.htm
Ohio State University. "22nd Amino Acid Synthesized And Added To Genetic Code Of E. Coli Bacteria." ScienceDaily. www.sciencedaily.com/releases/2004/09/040920070150.htm (accessed October 22, 2014).

Share This



More Plants & Animals News

Wednesday, October 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Cadaver Dogs Aid Search for More Victims of Suspected Indiana Serial Killer

Cadaver Dogs Aid Search for More Victims of Suspected Indiana Serial Killer

Reuters - US Online Video (Oct. 21, 2014) Police in Gary, Indiana are using cadaver dogs to search for more victims after a suspected serial killer confessed to killing at least seven women. Linda So reports. Video provided by Reuters
Powered by NewsLook.com
White Lion Cubs Unveiled to the Public

White Lion Cubs Unveiled to the Public

Reuters - Light News Video Online (Oct. 21, 2014) Visitors to Belgrade zoo meet a pair of three-week-old lion cubs for the first time. Tara Cleary reports. Video provided by Reuters
Powered by NewsLook.com
'Cadaver Dog' Sniffs out Human Remains

'Cadaver Dog' Sniffs out Human Remains

AP (Oct. 21, 2014) Where's a body buried? Buster's nose can often tell you. He's a cadaver dog, specially trained to find human remains and increasingly being used by law enforcement and accepted in courts. These dogs are helping solve even decades-old mysteries. (Oct. 21) Video provided by AP
Powered by NewsLook.com
White Lion Cubs Born in Belgrade Zoo

White Lion Cubs Born in Belgrade Zoo

AFP (Oct. 20, 2014) Two white lion cubs, an extremely rare subspecies of the African lion, were recently born at Belgrade Zoo. They are being bottle fed by zoo keepers after they were rejected by their mother after birth. Duration: 00:42 Video provided by AFP
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


Plants & Animals

Earth & Climate

Fossils & Ruins

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