This old version of Proteopedia is provided for student assignments while the new version is undergoing repairs. Content and edits done in this old version of Proteopedia after March 1, 2026 will eventually be lost when it is retired in about June of 2026.
Apply for new accounts at the new Proteopedia. Your logins will work in both the old and new versions.
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
