2gj9
From Proteopedia
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|PDB= 2gj9 |SIZE=350|CAPTION= <scene name='initialview01'>2gj9</scene>, resolution 2.000Å | |PDB= 2gj9 |SIZE=350|CAPTION= <scene name='initialview01'>2gj9</scene>, resolution 2.000Å | ||
|SITE= | |SITE= | ||
| - | |LIGAND= <scene name='pdbligand=ALF:TETRAFLUOROALUMINATE+ION'>ALF</scene>, <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene>, <scene name='pdbligand=RB:RUBIDIUM+ION'>RB</scene> and <scene name='pdbligand=GDP:GUANOSINE-5 | + | |LIGAND= <scene name='pdbligand=ALF:TETRAFLUOROALUMINATE+ION'>ALF</scene>, <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene>, <scene name='pdbligand=RB:RUBIDIUM+ION'>RB</scene> and <scene name='pdbligand=GDP:GUANOSINE-5'-DIPHOSPHATE'>GDP</scene> |
|ACTIVITY= | |ACTIVITY= | ||
|GENE= trmE, mnmE, thdF ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=562 Escherichia coli]) | |GENE= trmE, mnmE, thdF ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=562 Escherichia coli]) | ||
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[[Category: g-domain dimer]] | [[Category: g-domain dimer]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Mar 23 15:10:54 2008'' |
Revision as of 13:10, 23 March 2008
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| , resolution 2.000Å | |||||||
|---|---|---|---|---|---|---|---|
| Ligands: | , , and | ||||||
| Gene: | trmE, mnmE, thdF (Escherichia coli) | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
Structure of the MnmE G-domain in complex with GDP*AlF4-, Mg2+ and Rb+
Overview
MnmE, a Guanine nucleotide-binding protein conserved between bacteria and man, is involved in the modification of tRNAs. Here we provide biochemical and X-ray structural evidence for a new GTP-hydrolysis mechanism, where the G-domains of MnmE dimerise in a potassium-dependent manner and induce GTP hydrolysis. The structure in the presence of GDP-AlFx and potassium shows how juxtaposition of the subunits induces a conformational change around the nucleotide which reorients the catalytic machinery. A critical glutamate is positioned such as to stabilise or activate the attacking water. Potassium provides a positive charge into the catalytic site in a position analogous to the arginine finger in the Ras-RasGAP system. Mutational studies show that potassium-dependent dimerisation and GTP hydrolysis can be uncoupled and that interaction between the G-domains is a prerequisite for subsequent phosphoryl transfer. We propose a model for the juxtaposition of G-domains in the full-length protein and how it induces conformational changes in the putative tRNA-modification centre.
About this Structure
2GJ9 is a Single protein structure of sequence from Escherichia coli. Full crystallographic information is available from OCA.
Reference
Dimerisation-dependent GTPase reaction of MnmE: how potassium acts as GTPase-activating element., Scrima A, Wittinghofer A, EMBO J. 2006 Jun 21;25(12):2940-51. Epub 2006 Jun 8. PMID:16763562
Page seeded by OCA on Sun Mar 23 15:10:54 2008
Categories: Escherichia coli | Single protein | Scrima, A. | Wittinghofer, A. | ALF | GDP | MG | RB | Alpha-beta-sandwich | G-domain dimer
