New crystal structure sheds light on protein synthesis

Uppsala University researcher Maria Selmer, in cooperation with this year's Nobel Laureate in Chemistry, Venkatraman Ramakrishnan, and his research team, has succeeded for the first time in elucidating the crystal structure of a GTPase protein in ribosome-bound form. The findings were published today in the online edition of the journal Science and provide new insights into protein synthesis.

Genetic information, as encoded in mRNA, is transcribed into proteins at ribosomes. At various stages in this process, GTPase proteins assist the ribosomes in using guanosine triphosphate (GTP) as a source of energy. While the details of ribosomal structure have been known for some time (the discovery having been rewarded with this year's Nobel Prize in Chemistry), the mechanism by which GTPases bind to ribosomes remained unclear.

EF-G is the specific GTPase that controls the process by which mRNA strands are moved forward so that the each succeeding base triplet can be transcribed to an amino acid. The study in question involved researchers examining how EF-G interfaces with ribosomes and how fusidic acid, an antibiotic with clinical applications, prevents EF-G from detaching from ribosomes.

The crystal structure of a GTPase in its ribosome-bound form was elucidating for the first time, providing new insights into how EF-G controls the progress of mRNA strands through ribosomes.

"The findings increase our understanding of protein synthesis and of the functioning of fusidic acid at the molecular level," says Maria Selmer, a researcher at the Department of Cell and Molecular Biology at Uppsala University. "Our hope is that what we have learned will be of use in developing new and improved antibiotics with similar mechanisms."

For additional information, please contact Maria Selmer, Telephone: +46-18-471 41 77 or +46-70-598 83 91, E-mail: maria.selmer@icm.uu.se