2009/05/06

Researchers at CIC bioGUNE reveal evolution of prehistoric protein in the human body.

Research carried out by the Basque Centre for Biosciences, CIC bioGUNE, and the universities of Yale, Harvard and Oxford, published in this May's edition of PLoS Biology, shows that the enzyme that converts DNA into RNA has been conserved in the human body, surprisingly, since appearing in ancestral unicellular organisms, despite an evolutionary gulf of 2 billion years.

These organisms, called Sulfolobus, live in extreme environments such as volcanoes and salt flats with extremely high concentrations of sulphur, and they contain the enzyme multisubunit RNA polymerase. This polymerase is responsible for transcription, the process of converting DNA to RNA (which in turn is converted into proteins by ribosomes), although in human beings it carries out more complex functions.

The research published in PLoS Biology was led by Nicola Abrescia, an Italian researcher contracted by the Ikerbasque Foundation who recently joined the Structural Biology Unit at CIC bioGUNE, and Yakov Korkhin (a researcher at Yale and Harvard), as well as other colleagues from Oxford University.

Korkhin and Abrescia, together with their team, researched the polymerase enzyme by means of X-ray crystallography in the Structural Biology Unit at CIC bioGUNE. This is a method which scatters X-rays through tiny crystals of proteins or nucleic acids to reconstruct their three-dimensional structure. The team has been able to determine the whole architecture of the enzyme and its evolutionary path.

This research is highly significant because, according to Abrescia, "it describes for the first time the whole enzymatic machinery of this organism and may help us to understand where we come from and how evolution has shaped us so that we can do more complex tasks".