Navigation Links
Study shows adding UV light helps form 'Missing G' of RNA building blocks
Date:6/14/2010

For scientists attempting to understand how the building blocks of RNA originated on Earth, guanine -- the G in the four-letter code of life -- has proven to be a particular challenge. While the other three bases of RNA -- adenine (A), cytosine (C) and uracil (U) -- could be created by heating a simple precursor compound in the presence of certain naturally occurring catalysts, guanine had not been observed as a product of the same reactions.

By adding ultraviolet light to a model prebiotic reaction, researchers from the Georgia Institute of Technology and the University of Roma, "La Sapienza", have discovered a route by which the missing guanine could have been formed. They also found that the RNA bases may have been easier to form than previously thought -- suggesting that starting life on Earth might not have been so difficult after all.

The findings are reported June 14, 2010 in the journal ChemBioChem. This collaborative work is supported by the National Science Foundation (NSF), the National Aeronautics and Space Administration, and the European Space Agency. The NSF funding is provided through the Center for Chemical Evolution at Georgia Tech.

Understanding how life emerged is one of the greatest scientific challenges. There is considerable evidence that the evolution of life passed through an early stage in which RNA played a more central role, before DNA and protein enzymes appeared.

Recent efforts to understand the prebiotic formation of the building blocks of RNA have focused on the chemical formamide (H2NCOH) as a potential starting material to create the RNA bases because it contains the four required elements -- carbon, hydrogen, oxygen and nitrogen -- and because of its stability, reactivity and low volatility compared to water. Previous reports have shown that these nucleic acid components -- with the exception of guanine -- can be synthesized by heating formamide to 160 degrees Celsius in the presence of mineral catalysts.

In their ChemBioChem paper, the researchers show for the first time that guanine can be produced by subjecting a solution of formamide to ultraviolet radiation during heating. The trace gaunine yield was greatly enhanced when minerals and photons were used together. In addition, production of adenine and a related molecule called hypoxanthine increased when ultraviolet light was added to the heating process -- a 15-fold increase was seen in adenine yield.

"These results potentially relax some of the requirements and reactions necessary to get life started, because formamide molecules would not have had to be in contact with a particular type of rock when heated on the prebiotic Earth, if the formamide was exposed to direct sunlight during heating," said Nicholas Hud, a professor in the Georgia Tech School of Chemistry and Biochemistry.

The study demonstrated that guanine, adenine and hypoxanthine can be produced at lower temperatures than previously reported, even in the absence of minerals, as long as photons are added.

"For these experiments we built a very simple reaction chamber with an inexpensive 254-nanometer photon source to simulate conditions that could have been present on early Earth," explained Thomas Orlando, also a professor in Georgia Tech's School of Chemistry and Biochemistry. "We didn't need extremely sophisticated experimental systems or expensive lasers; however, we did use sophisticated mass spectrometers to analyze the resulting complex chemical mixtures."

The Hud and Orlando laboratories conducted experiments by heating formamide to 130 degrees Celsius -- 30 degrees cooler than previous experiments -- and shining ultraviolet light onto it.

"Our work has allowed us to consider a different type of 'primordial soup' than what has previously been considered possible starting conditions for life," said Orlando. "Our model prebiotic reaction is attractive because most aspects of the process were likely to occur on the early Earth and it reduces chemical constraints."

The authors suggest that aqueous pools containing small amounts of formamide may have existed on the early Earth. During hot and dry periods, water evaporation could have given rise to concentrated solutions of formamide and exposed mineral surfaces coated with formamide.

By conducting additional experiments at 100 degrees Celsius with solutions of formamide and water, the researchers confirmed that this "drying pool" model could give rise to solutions of formamide capable of producing the compounds found in their earlier experiments.

"While there is still a lot of chemistry required for us to better understand the formation of biological molecules needed for life, these one-pot reactions that occur due to the synergy of thermal and photochemical processes tell us that the chemical and environmental requirements to produce life are probably less restrictive than we once thought," added Hud.


'/>"/>

Contact: Abby Vogel Robinson
abby@innovate.gatech.edu
404-385-3364
Georgia Institute of Technology Research News
Source:Eurekalert  

Related biology news :

1. Suspended animation protects against lethal hypothermia, study shows
2. UAB study confirms link between depression, abdominal obesity
3. UMCES Horn Point Laboratory scientists to study oil spill effects in Gulf of Mexico
4. CoLucid Pharmaceuticals, Inc. announces study data documenting oral efficacy of lasmiditan (COL-144), a selective 5-HT1F receptor agonist, in the treatment of acute migraine attacks
5. University of Washington institute to get as much as $100 million to study atmosphere, ocean
6. Study of microRNA helps NIH scientists unlock secrets of immune cells
7. Study finds epigenetic similarities between Wilms tumor cells and normal kidney stem cells
8. UM School of Medicine study finds vaginal microbes vary among healthy women
9. Nature cover study provides new standards for reliable fisheries
10. Neural tissue contains imbalanced levels of proteins, U-M study finds
11. Oil spill reshapes sweeping new study of oyster reefs -- Virginia to Florida
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Study shows adding UV light helps form 'Missing G' of RNA building blocks
(Date:3/15/2016)... , March 15, 2016 --> ... published by Transparency Market Research "Digital Door Lock Systems Market ... 2015 - 2023," the global digital door lock systems market ... in 2014 and is forecast to grow at a CAGR ... micro, small and medium enterprises (MSMEs) across the world and ...
(Date:3/11/2016)... 2016 http://www.apimages.com ) - --> ... available at AP Images ( http://www.apimages.com ) - ... to produce the new refugee identity cards. DERMALOG will be unveiling ... in Hanover next week.   --> ... used to produce the new refugee identity cards. DERMALOG will be ...
(Date:3/9/2016)... This BCC Research report provides an overview ... Sequencing (RNA Seq) market for the years 2015, 2016 ... reagents, data analysis, and services. Use this ... market such as RNA-Sequencing tools and reagents, RNA-Sequencing data ... each segment and forecast their market growth, future trends ...
Breaking Biology News(10 mins):
(Date:5/3/2016)... ... 03, 2016 , ... Leading CEOs from biotech, pharmaceutical, and ... June 1st at The Four Seasons Hotel Boston. , The Boston CEO Conference ... exclusive access to key decision makers who influence deal making and investment. Attendees ...
(Date:5/3/2016)... LONDON , May 3, 2016 ... Report Assessing Developers and Producers of Those Competitor Biologics  ... Guide to Companies, Activities and Prospects ,  ... drug companies? And what are their sales potentials? ... There you see results, trends, opportunities and revenue forecasting. ...
(Date:5/2/2016)... YORK , May 2, 2016 ... announces that its technology partner Mannin Research Inc. will ... Ophthalmology (ARVO), which takes place from May 1-5, 2016 ... executives will be meeting with its vendors and research ... explore business development goals and other collaborative opportunities for ...
(Date:4/29/2016)... ... April 30, 2016 , ... The MIT bioLogic design team has won ... explored how bacterial properties can be applied to fabric and formed into living interfaces ... in response to humidity change. The team harvested Natto cells and applied them to ...
Breaking Biology Technology: