Wednesday, 30 November 2011

Protein displacement has implications for understanding of evolution

An international team led by scientists from the School of Biology, conducting research on organisms found in Yellowstone National Park in the USA, have used biochemistry and bioinformatics to demonstrate the displacement of an essential, "universal" protein by a completely unrelated one in one branch of the tree of life. It suggests that even the most fundamental, ubiquitous proteins can be replaced during evolution.
Proteins are the major structural and operational components of cells. Even the simplest organisms possess hundreds of different proteins, whereas more complex organisms typically have many thousand. Because all living beings, from microbes to humans, are related by evolution, they share a core set of proteins in common. Proteins perform fundamental roles in key metabolic processes and in the processing of information from DNA via RNA to proteins. A notable example is the single-stranded DNA binding protein, SSB, which is essential for DNA replication and repair and is widely considered to be one of the few core universal proteins shared by all life forms. The research demonstrates that one branch of the tree of life has lost this "ubiquitous" protein and replaced it with another, unrelated one. This finding has important implications for our understanding of the plasticity of evolution. [abstract][more]