2gj9: Difference between revisions
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[[Image:2gj9.gif|left|200px]] | [[Image:2gj9.gif|left|200px]] | ||
'''Structure of the MnmE G-domain in complex with GDP*AlF4-, Mg2+ and Rb+''' | {{Structure | ||
|PDB= 2gj9 |SIZE=350|CAPTION= <scene name='initialview01'>2gj9</scene>, resolution 2.000Å | |||
|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'-DIPHOSPHATE'>GDP</scene> | |||
|ACTIVITY= | |||
|GENE= trmE, mnmE, thdF ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=562 Escherichia coli]) | |||
}} | |||
'''Structure of the MnmE G-domain in complex with GDP*AlF4-, Mg2+ and Rb+''' | |||
==Overview== | ==Overview== | ||
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==About this Structure== | ==About this Structure== | ||
2GJ9 is a [ | 2GJ9 is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2GJ9 OCA]. | ||
==Reference== | ==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:[http:// | 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:[http://www.ncbi.nlm.nih.gov/pubmed/16763562 16763562] | ||
[[Category: Escherichia coli]] | [[Category: Escherichia coli]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
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[[Category: g-domain dimer]] | [[Category: g-domain dimer]] | ||
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Mar 20 17:05:22 2008'' | ||
Revision as of 15:05, 20 March 2008
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| 2gj9, resolution 2.000Å | |||||||||||||
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| Ligands: | ALF, MG, RB and GDP | ||||||||||||
| 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
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