Researchers develop model of 'near-optimal' genetic code

Aug 28, 2013

Researchers have created a model that may explain the complexities of the origins of life. Their work, which appears in the Journal of the Royal Society Interface, offers new insights into how RNA signaling likely developed into the modern "genetic code."

"Our model shows that today's probably resulted from a combination of selective forces and random chance," explained Justin Jee, a doctoral student at NYU School of Medicine and the paper's lead author.

The study's other co-authors included: Bud Mishra, who has appointments at NYU's Courant Institute of Mathematical Sciences and the Sackler Institute of Graduate Biomedical Sciences at NYU School of Medicine; Andrew Sundstrom of the Courant Institute; and Steven Massey, an assistant professor in the University of Puerto Rico's Department of Biology.

The researchers sought to account for the composition of the genetic code, which allows proteins to be built from amino acids with high specificity based on information stored in a RNA or DNA genome. This translation process between the and amino acids is remarkably and mysteriously universal; the same code is shared in all organisms from bacteria to human beings. At the same time, the genetic code is nearly, but not completely, optimal in terms of how "good" it is at specifying particular amino acids for particular nucleic acid sequences.

Since the code's discovery in the 1960's, researchers have wondered: how is it that a near-optimal code became so universal?

To address this question, the researchers created a model of genetic code evolution in which multiple "translating" RNAs and "genomic" RNAs competed for survival. Specifically, the translating RNAs were able to link together based on information stored in genomic RNA, but with varying levels of specificity.

In running of RNA interactions, they could see two phenomena. First, it was necessary for the translating and genomic RNAs to organize into cells, which aided the coordination of a code between the translating and genomic RNAs. Second, selective forces led a single set of translating RNAs to dominate the population. In other words, the emergence of a single, universal, near-optimal code was a natural outcome of the model. Even more remarkably, the results occurred under realistic conditions—specifically, they held under parameters such as protein lengths and rates of mutation that likely existed in a natural RNA world.

"The most elegant ideas in this paper are rather obvious consequences of a well-studied model based on sender-receiver games," noted Mishra, the paper's senior author. "Yet the results are still very surprising because they suggest, for example, that proteins, the most prized molecules of biology, might have had their origin as undesirable toxic trash. Other studies based on phylogenomic analysis seem to be coming to similar conclusions independently."

Explore further: The origin of the language of life

More information: rsif.royalsocietypublishing.or… .1098/rsif.2013.0614

Related Stories

Study offers insight into the origin of the genetic code

Aug 26, 2013

An analysis of enzymes that load amino acids onto transfer RNAs—an operation at the heart of protein translation—offers new insights into the evolutionary origins of the modern genetic code, researchers ...

Simplifying genetic codes to look back in time

Aug 24, 2012

(Phys.org)— Daisuke Kiga and co-workers at the Department of Computational Intelligence and Systems Science at Tokyo Institute of Technology, together with researchers across Japan, have shown that simpler versions of the ...

Recommended for you

The origin of the language of life

Dec 19, 2014

The genetic code is the universal language of life. It describes how information is encoded in the genetic material and is the same for all organisms from simple bacteria to animals to humans. However, the ...

Quest to unravel mysteries of our gene network

Dec 18, 2014

There are roughly 27,000 genes in the human body, all but a relative few of them connected through an intricate and complex network that plays a dominant role in shaping our physiological structure and functions.

EU court clears stem cell patenting

Dec 18, 2014

A human egg used to produce stem cells but unable to develop into a viable embryo can be patented, the European Court of Justice ruled on Thursday.

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.