1dar: Difference between revisions

[[Image:1dar.gif|left|200px]]<br /><applet load="1dar" size="350" color="white" frame="true" align="right" spinBox="true"  

BACKGROUND: Elongation factor G (EF-G) catalyzes the translocation step of translation. During translocation EF-G passes through four main conformational states: the GDP complex, the nucleotide-free state, the GTP complex, and the GTPase conformation. The first two of these conformations have been previously investigated by crystallographic methods. RESULTS: The structure of EF-G-GDP has been refined at 2.4 A resolution. Comparison with the nucleotide-free structure reveals that, upon GDP release, the phosphate-binding loop (P-loop) adopts a closed conformation. This affects the position of helix CG, the switch II loop and domains II, IV and V. Asp83 has a conformation similar to the conformation of the corresponding residue in the EF-Tu/EF-Ts complex. The magnesium ion is absent in EF-G-GDP. CONCLUSIONS: The results illustrate that conformational changes in the P-loop can be transmitted to other parts of the structure. A comparison of the structures of EF-G and EF-Tu suggests that EF-G, like EF-Tu, undergoes a transition with domain rearrangements. The conformation of EF-G-GDP around the nucleotide-binding site may be related to the mechanism of nucleotide exchange.

1DAR is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Thermus_thermophilus Thermus thermophilus] with <scene name='pdbligand=GDP:'>GDP</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. The following page contains interesting information on the relation of 1DAR with [[http://pdb.rcsb.org/pdb/static.do?p=education_discussion/molecule_of_the_month/pdb81_1.html Elongation Factors]]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1DAR OCA].  

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