1tui
From Proteopedia
(New page: 200px<br /> <applet load="1tui" size="450" color="white" frame="true" align="right" spinBox="true" caption="1tui, resolution 2.7Å" /> '''INTACT ELONGATION FA...) |
|||
| Line 1: | Line 1: | ||
| - | [[Image:1tui.gif|left|200px]]<br /> | + | [[Image:1tui.gif|left|200px]]<br /><applet load="1tui" size="350" color="white" frame="true" align="right" spinBox="true" |
| - | <applet load="1tui" size=" | + | |
caption="1tui, resolution 2.7Å" /> | caption="1tui, resolution 2.7Å" /> | ||
'''INTACT ELONGATION FACTOR TU IN COMPLEX WITH GDP'''<br /> | '''INTACT ELONGATION FACTOR TU IN COMPLEX WITH GDP'''<br /> | ||
==Overview== | ==Overview== | ||
| - | BACKGROUND: Elongation factor Tu (EF-Tu) in its GTP conformation is a | + | BACKGROUND: Elongation factor Tu (EF-Tu) in its GTP conformation is a carrier of aminoacylated tRNAs (aa-tRNAs) to the ribosomal A site during protein biosynthesis. The ribosome triggers GTP hydrolysis, resulting in the dissociation of EF-Tu-GDP from the ribosome. The affinity of EF-Tu for other molecules involved in this process, some of which are unknown, is regulated by two regions (Switch I and Switch II) that have different conformations in the GTP and GDP forms. The structure of the GDP form of EF-Tu is known only as a trypsin-modified fragment, which lacks the Switch I, or effector, domain. The aim of this work was to establish the overall structure of intact EF-Tu-GDP, in particular the structure of the effector domain. RESULTS: The crystal structures of intact EF-Tu-GDP from Thermus aquaticus and Escherichia coli have been determined at resolutions of 2.7 A and 3.8 A, respectively. The structures confirm the domain orientation previously found in the structure of partially trypsin-digested EF-Tu-GDP. The structures of the effector region in T. aquaticus and E. coli EF-Tu-GDP are very similar. The C-terminal part of the effector region of EF-Tu-GDP is a beta hairpin; in EF-Tu-GTP, this region forms an alpha helix. This conformational change is not a consequence of crystal packing. CONCLUSIONS: EF-Tu undergoes major conformational changes upon GTP hydrolysis. Unlike other GTP-binding proteins, EF-Tu exhibits a dramatic conformational change in the effector region, involving an unwinding of a small helix and the formation of a beta hairpin structure. This change is presumably involved in triggering the release of tRNA, and EF-Tu, from the ribosome. |
==About this Structure== | ==About this Structure== | ||
| - | 1TUI is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Thermus_aquaticus Thermus aquaticus] with MG and GDP as [http://en.wikipedia.org/wiki/ligands ligands]. The following page contains interesting information on the relation of 1TUI 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:// | + | 1TUI is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Thermus_aquaticus Thermus aquaticus] with <scene name='pdbligand=MG:'>MG</scene> and <scene name='pdbligand=GDP:'>GDP</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. The following page contains interesting information on the relation of 1TUI 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=1TUI OCA]. |
==Reference== | ==Reference== | ||
| Line 27: | Line 26: | ||
[[Category: protein biosynthesis]] | [[Category: protein biosynthesis]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 15:17:28 2008'' |
Revision as of 13:17, 21 February 2008
|
INTACT ELONGATION FACTOR TU IN COMPLEX WITH GDP
Overview
BACKGROUND: Elongation factor Tu (EF-Tu) in its GTP conformation is a carrier of aminoacylated tRNAs (aa-tRNAs) to the ribosomal A site during protein biosynthesis. The ribosome triggers GTP hydrolysis, resulting in the dissociation of EF-Tu-GDP from the ribosome. The affinity of EF-Tu for other molecules involved in this process, some of which are unknown, is regulated by two regions (Switch I and Switch II) that have different conformations in the GTP and GDP forms. The structure of the GDP form of EF-Tu is known only as a trypsin-modified fragment, which lacks the Switch I, or effector, domain. The aim of this work was to establish the overall structure of intact EF-Tu-GDP, in particular the structure of the effector domain. RESULTS: The crystal structures of intact EF-Tu-GDP from Thermus aquaticus and Escherichia coli have been determined at resolutions of 2.7 A and 3.8 A, respectively. The structures confirm the domain orientation previously found in the structure of partially trypsin-digested EF-Tu-GDP. The structures of the effector region in T. aquaticus and E. coli EF-Tu-GDP are very similar. The C-terminal part of the effector region of EF-Tu-GDP is a beta hairpin; in EF-Tu-GTP, this region forms an alpha helix. This conformational change is not a consequence of crystal packing. CONCLUSIONS: EF-Tu undergoes major conformational changes upon GTP hydrolysis. Unlike other GTP-binding proteins, EF-Tu exhibits a dramatic conformational change in the effector region, involving an unwinding of a small helix and the formation of a beta hairpin structure. This change is presumably involved in triggering the release of tRNA, and EF-Tu, from the ribosome.
About this Structure
1TUI is a Single protein structure of sequence from Thermus aquaticus with and as ligands. The following page contains interesting information on the relation of 1TUI with [Elongation Factors]. Full crystallographic information is available from OCA.
Reference
Helix unwinding in the effector region of elongation factor EF-Tu-GDP., Polekhina G, Thirup S, Kjeldgaard M, Nissen P, Lippmann C, Nyborg J, Structure. 1996 Oct 15;4(10):1141-51. PMID:8939739
Page seeded by OCA on Thu Feb 21 15:17:28 2008
