The study, in the journal Structure, reveals that after eons of gradual evolution, proteins suddenly experienced a “big bang” of innovation.
The active regions of many proteins, called domains, combined with each other or split apart to produce a host of structures that had never been seen before. This explosion of new forms coincided with the rapidly increasing diversity of the three superkingdoms of life (bacteria; the microbes known as archaea; and eukarya, the group that includes animals, plants, fungi and many other organisms).
Lead author Gustavo Caetano-Anollés, a professor of bioinformatics in the department of crop sciences at the University of Illinois and an affiliate of the Institute for Genomic Biology, has spent years studying protein structures – he calls them “architectures” – which he suggests offer a reliable record of evolutionary events.
By conducting a census of all the domains that appear in different groups of organisms and comparing the protein repertoires of hundreds of different groups, the researchers were able to construct a timeline of protein evolution that relates directly to the history of life.
“The history of the protein repertoire should match the history of the entire organism because the organism is made up of all those pieces,” Caetano-Anollés said.
He and his co-author, postdoctoral researcher Minglei Wang, were interested in tracing how proteins make use of their domains, or groups of domains, to accomplish various tasks. These domains or domain clusters can be thought of as “modules” that fit together in various ways to achieve different ends.
Unlike the sequence of amino acids in a protein, which is highly susceptible to change, the protein modules found today in living organisms have endured because they perform critical tasks beneficial to the organisms that host them, Caetano-Anollés said.
“These modules are resistant to change, they are highly integrated and they are used in different contexts,” he said.
By tracing the history of the modules, the researchers were able to build a rough timeline of protein evolution. It revealed that before the three superkingdoms began to emerge, most proteins contained only single domains that performed a lot of tasks.
“As time progressed, these domains started to combine with others and they became very specialized,” Caetano-Anollés said. This eventually led to the big bang of protein architectures.
“Exactly at the time of the big bang,” many of the combined domains began to split apart, creating numerous single-domain modules again, he said. But these new modules were much more efficient and specialized than their ancient predecessors had been.
“This makes a lot of sense,” Caetano-Anollés said. “As you become more complex, you would want to fine-tune things, to do things in a more tailored way.”
The protein modules of the three superkingdoms also began to diverge more dramatically from one another, with the eukarya (the group that includes plants and animals) hosting the greatest diversity of modules.
“This explosion of diversity allowed the eukarya to do things with their proteins that other organisms could not do,” Caetano-Anollés said.
Diana Yates | University of Illinois
Researchers invent tiny, light-powered wires to modulate brain's electrical signals
21.02.2018 | University of Chicago
The “Holy Grail” of peptide chemistry: Making peptide active agents available orally
21.02.2018 | Technische Universität München
For the first time, a team of researchers at the Max-Planck Institute (MPI) for Polymer Research in Mainz, Germany, has succeeded in making an integrated circuit (IC) from just a monolayer of a semiconducting polymer via a bottom-up, self-assembly approach.
In the self-assembly process, the semiconducting polymer arranges itself into an ordered monolayer in a transistor. The transistors are binary switches used...
Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale
Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...
For photographers and scientists, lenses are lifesavers. They reflect and refract light, making possible the imaging systems that drive discovery through the microscope and preserve history through cameras.
But today's glass-based lenses are bulky and resist miniaturization. Next-generation technologies, such as ultrathin cameras or tiny microscopes, require...
Scientists from the University of Zurich have succeeded for the first time in tracking individual stem cells and their neuronal progeny over months within the intact adult brain. This study sheds light on how new neurons are produced throughout life.
The generation of new nerve cells was once thought to taper off at the end of embryonic development. However, recent research has shown that the adult brain...
Theoretical physicists propose to use negative interference to control heat flow in quantum devices. Study published in Physical Review Letters
Quantum computer parts are sensitive and need to be cooled to very low temperatures. Their tiny size makes them particularly susceptible to a temperature...
15.02.2018 | Event News
13.02.2018 | Event News
12.02.2018 | Event News
21.02.2018 | Life Sciences
21.02.2018 | Life Sciences
21.02.2018 | Materials Sciences