Abstract
Translation elongation factor EF-Tu belongs to the superfamily of guanine-nucleotide binding proteins, which play key cellular roles as regulatory switches. All G-proteins require activation via exchange of GDP for GTP to carry out their respective tasks. Often, guanine-nucleotide exchange factors are essential to this process. During translation, EF-Tu:GTP transports aminoacylated tRNA to the ribosome. GTP is hydrolyzed during this process, and subsequent reactivation of EF-Tu is catalyzed by EF-Ts. The reaction path of guanine-nucleotide exchange is structurally poorly defined for EF-Tu and EF-Ts. We have determined the crystal structures of the following reaction intermediates: two structures of EF-Tu:GDP:EF-Ts (2.2 and 1.8 Å resolution), EF-Tu:PO4:EF-Ts (1.9 Å resolution), EF-Tu:GDPNP:EF-Ts (2.2 Å resolution) and EF-Tu:GDPNP:pulvomycin:Mg(2+):EF-Ts (3.5 Å resolution). These structures provide snapshots throughout the entire exchange reaction and suggest a mechanism for the release of EF-Tu in its GTP conformation. An inferred sequence of events during the exchange reaction is presented.
Originalsprog | Engelsk |
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Tidsskrift | Journal of Structural Biology |
Vol/bind | 191 |
Nummer | 1 |
Sider (fra-til) | 10-21 |
Antal sider | 12 |
ISSN | 1047-8477 |
DOI | |
Status | Udgivet - 11 jun. 2015 |