One of the biggest challenges in molecular evolution studies is to gain informations about the evolution of protein tertiary structures. When we try to determine the evolutionary origins of proteins, we basically consider the structure similarities between contemporary proteins, since we don’t generally have enough paleo- materials to analyze. Therefore, we can only abstract a putative model of the ancestors of proteins.
The international team leaded by Sanchez- Ruiz from the spanish University of Granada overcome this problem resolving the x-ray structure of Precambrian thiredoxins. In an earlier paper, Sanchez- Ruiz and his collaborators constructed a phylogenetic tree of thioredoxins- proteins that are present in the three domains of life (archaea, bacteria and eukariotes).
The tree leaded the way for the resurrection of Precambrian proteins in the labotratory and the characterization of their features. In the new study, published on structure the last august 8th, Sanchez- Ruiz teamed up with Jose Gavira from the Andalutian Institute of Earth Sciences (Spanish National Research Council — University of Granada) to analyze the X-ray chrystal structure of the resurrected proteins. The finidings are simply striking. The present- day thireodoxins are remarkably similar to those that existed 4 billions of years ago, a period really close to the origins of life. This is consistant to the punctuated- equilibrium model of evolution, in wich protein structures changes occur intermittently in short periods, with long periods of conservation.
This work is remarkable because of his capability to show the full potential of theoretical and base- research approaches in biology. The same author underlines it as it follows:
In addition to uncovering the basic principles of protein structure evolution, our approach will provide invaluable information regarding how the 3D structure of a protein is encoded by its amino acid sequence. (…) It could also provide information about how to design proteins with novel structures — an important goal in protein engineering and biotechnology.
For a theoretical biology blog it is very important to remark this. The base research approaches and theoretical contributions play a crucial role for the development of applied fields such as biomedical research and biotechnology.