Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Scientists discover the evolutionary link between protein structure and function


Proteins are more than a dietary requirement. This diverse set of molecules powers nearly all of the cellular operations in a living organism. Scientists may know the structure of a protein or its function, but haven't always been able to link the two.

"The big problem in biology is the question of how a protein does what it does. We think the answer rests in protein evolution," says University of Illinois professor and bioinformatician Gustavo Caetano-Anollés.

The two loops, shown in gold near the bottom of the protein structure, delimit the pocket where heme subunit resides and where oxygenation occurs.

Credit: Gustavo Caetano-Anollés

Geologists have found remnants of life preserved in rock billions of years old. In some cases, preservation of microbes and tissues has been so good that microscopic cellular structures that were once associated with specific proteins, can be detected.

This geological record gives scientists a hidden connection to the evolutionary history of protein structures over incredibly long time periods. But, until now, it hasn't always been possible to link function with those structures to know how proteins were behaving in cells billions of years ago, compared with today.

"For the first time, we have traced evolution onto a biological network," Caetano-Anollés notes.

Caetano-Anollés and graduate students Fayez Aziz and Kelsey Caetano-Anollés used networks to investigate the linkage between protein structure and molecular function. They built a timeline of protein structures spanning 3.8 billion years across the geological record, but needed a way to connect the structures with their functions. To do that, they looked at the genetic makeup of hundreds of organisms.

"It turns out that there are little snippets in our genes that are incredibly conserved over time," Caetano-Anollés says. "And not just in human genomes. When we look at higher organisms, such as plants, fungi and animals, as well as bacteria, archaea, and viruses, the same snippets are always there. We see them over and over again."

The research team found that these tiny gene segments tell proteins to produce "loops," which are the tiniest structural units in a protein. When loops come together, they create active sites, or molecular pockets, which give proteins their function. For example, hemoglobin, the protein that carries oxygen in blood, has two loops which create the active site that binds oxygen. The loops combine to create larger protein structures called domains.

Remarkably, the new study shows that loops have been repeatedly recruited to perform new functions and that the process has been active and ongoing since the beginning of life.

"This recruitment is important for understanding biological diversity," Caetano-Anollés says.

One important aspect of the study relates to the actual linkage between domain structure and functional loops. The researchers found that this linkage is characterized by an unanticipated property that unfolds in time, an "emergent" property known as hierarchical modularity.

"Loops are cohesive modules, as are domains, proteins, cells, organs, and bodies." Caetano-Anollés explains. "We are all made of cohesive modules, including our human bodies. That's hierarchical modularity: the building of small cohesive parts into larger and increasingly complex wholes."

Hierarchical modularity also exists in manmade networks, such as the internet. For example, each router represents a "node" that pushes information to different computers. When millions of computers interact with each other online, larger and more complex entities emerge. Caetano-Anollés suggests that the evolution of manmade networks could be mapped in the same way as the evolution of biological networks.

"From a computer science point of view, few people have been exploring how to track networks in time. Imagine exploring how the internet grows and changes when new routers are added, are disconnected, or network with each other. It's a daunting task because there are millions of routers to track and internet communication can be highly dynamic. In our study, we are showcasing how you can do it with a very small network," Caetano-Anollés explains.

The methods developed by Caetano-Anollés and his team now have the potential to explain how change is capable of structuring systems as varied as the internet, social networks, or the collective of all proteins in an organism.


The article, "The early history and emergence of molecular functions and modular scale-free network behavior," is published in Scientific Reports. M. Fayez Aziz and Kelsey Caetano-Anollés, also from the University of Illinois, co-authored the report. Full text of the article can be found at:

Media Contact

Lauren Quinn


Lauren Quinn | EurekAlert!

Further reports about: Agricultural protein structure protein structures proteins

More articles from Life Sciences:

nachricht First time-lapse footage of cell activity during limb regeneration
25.10.2016 | eLife

nachricht Phenotype at the push of a button
25.10.2016 | Institut für Pflanzenbiochemie

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Etching Microstructures with Lasers

Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.

This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...

Im Focus: Light-driven atomic rotations excite magnetic waves

Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion

Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Ice shelf vibrations cause unusual waves in Antarctic atmosphere

25.10.2016 | Earth Sciences

Fluorescent holography: Upending the world of biological imaging

25.10.2016 | Power and Electrical Engineering

Etching Microstructures with Lasers

25.10.2016 | Process Engineering

More VideoLinks >>>