Lynn Kamerlin
Professor
Energetics of activation of GTP hydrolysis on the ribosome
Author
Summary, in English
Several of the steps in protein synthesis on the ribosome utilize hydrolysis of guanosine triphosphate (GTP) as the driving force. This reaction is catalyzed by translation factors that become activated upon binding to the ribosome. The recently determined crystal structure of an elongation factor-Tu ternary complex bound to the ribosome allows the energetics of GTP activation to be explored by computer simulations. A central problem regards the role of the universally conserved histidine, which has been proposed to act as a general base for guanosine triphosphate hydrolysis. Here we report a detailed energetic and structural analysis of different possible protonation states that could be involved in activation of the reaction. We show that the histidine cannot act as a general base, but must be protonated and in its active conformation to promote GTP hydrolysis. We further show that the sarcin-ricin loop of the ribosome spontaneously drives the histidine into the correct conformation for GTP activation.
Publishing year
2013
Language
English
Publication/Series
Nature Communications
Volume
4
Document type
Journal article
Publisher
Nature Publishing Group
Keywords
- Catalytic Domain
- Energy Metabolism
- GTP Phosphohydrolases/chemistry
- Guanosine Triphosphate/metabolism
- Hydrolysis
- Models, Molecular
- Ribosomes/metabolism
Status
Published
ISBN/ISSN/Other
- ISSN: 2041-1723