1nv8: Difference between revisions
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[[Image: | ==N5-glutamine methyltransferase, HemK== | ||
<StructureSection load='1nv8' size='340' side='right' caption='[[1nv8]], [[Resolution|resolution]] 2.20Å' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[1nv8]] is a 2 chain structure with sequence from [http://en.wikipedia.org/wiki/Thermotoga_maritima Thermotoga maritima]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1NV8 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1NV8 FirstGlance]. <br> | |||
</td></tr><tr><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=MEQ:N5-METHYLGLUTAMINE'>MEQ</scene>, <scene name='pdbligand=SAM:S-ADENOSYLMETHIONINE'>SAM</scene><br> | |||
<tr><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[1nv9|1nv9]]</td></tr> | |||
<tr><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">HemK ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=2336 Thermotoga maritima])</td></tr> | |||
<tr><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1nv8 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1nv8 OCA], [http://www.rcsb.org/pdb/explore.do?structureId=1nv8 RCSB], [http://www.ebi.ac.uk/pdbsum/1nv8 PDBsum]</span></td></tr> | |||
<table> | |||
== Evolutionary Conservation == | |||
[[Image:Consurf_key_small.gif|200px|right]] | |||
Check<jmol> | |||
<jmolCheckbox> | |||
<scriptWhenChecked>select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/nv/1nv8_consurf.spt"</scriptWhenChecked> | |||
<scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked> | |||
<text>to colour the structure by Evolutionary Conservation</text> | |||
</jmolCheckbox> | |||
</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/chain_selection.php?pdb_ID=2ata ConSurf]. | |||
<div style="clear:both"></div> | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
Posttranslational methylation of release factors on the glutamine residue of a conserved GGQ motif is required for efficient termination of protein synthesis. This methylation is performed by an N(5)-glutamine methyltransferase called PrmC/HemK, whose crystal structure we report here at 2.2 A resolution. The electron density at the active site appears to contain a mixture of the substrates, S-adenosyl-L-methionine (AdoMet) and glutamine, and the products, S-adenosyl-L-homocysteine (AdoHcy) and N(5)-methylglutamine. The C-terminal domain of PrmC adopts the canonical AdoMet-dependent methyltransferase fold and shares structural similarity with the nucleotide N-methyltransferases in the active site, including use of a conserved (D/N)PPY motif to select and position the glutamine substrate. Residues of the PrmC (197)NPPY(200) motif form hydrogen bonds that position the planar Gln side chain such that the lone-pair electrons on the nitrogen nucleophile are oriented toward the methyl group of AdoMet. In the product complex, the methyl group remains pointing toward the sulfur, consistent with either an sp(3)-hybridized, positively charged Gln nitrogen, or a neutral sp(2)-hybridized nitrogen in a strained conformation. Due to steric overlap within the active site, proton loss and formation of the neutral planar methylamide product are likely to occur during or after product release. These structures, therefore, represent intermediates along the catalytic pathway of PrmC and show how the (D/N)PPY motif can be used to select a wide variety substrates. | |||
Structures along the catalytic pathway of PrmC/HemK, an N5-glutamine AdoMet-dependent methyltransferase.,Schubert HL, Phillips JD, Hill CP Biochemistry. 2003 May 20;42(19):5592-9. PMID:12741815<ref>PMID:12741815</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
== References == | |||
<references/> | |||
__TOC__ | |||
</StructureSection> | |||
== | |||
< | |||
[[Category: Thermotoga maritima]] | [[Category: Thermotoga maritima]] | ||
[[Category: Hill, C P.]] | [[Category: Hill, C P.]] | ||
Revision as of 20:23, 28 September 2014
N5-glutamine methyltransferase, HemKN5-glutamine methyltransferase, HemK
Structural highlights
Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedPosttranslational methylation of release factors on the glutamine residue of a conserved GGQ motif is required for efficient termination of protein synthesis. This methylation is performed by an N(5)-glutamine methyltransferase called PrmC/HemK, whose crystal structure we report here at 2.2 A resolution. The electron density at the active site appears to contain a mixture of the substrates, S-adenosyl-L-methionine (AdoMet) and glutamine, and the products, S-adenosyl-L-homocysteine (AdoHcy) and N(5)-methylglutamine. The C-terminal domain of PrmC adopts the canonical AdoMet-dependent methyltransferase fold and shares structural similarity with the nucleotide N-methyltransferases in the active site, including use of a conserved (D/N)PPY motif to select and position the glutamine substrate. Residues of the PrmC (197)NPPY(200) motif form hydrogen bonds that position the planar Gln side chain such that the lone-pair electrons on the nitrogen nucleophile are oriented toward the methyl group of AdoMet. In the product complex, the methyl group remains pointing toward the sulfur, consistent with either an sp(3)-hybridized, positively charged Gln nitrogen, or a neutral sp(2)-hybridized nitrogen in a strained conformation. Due to steric overlap within the active site, proton loss and formation of the neutral planar methylamide product are likely to occur during or after product release. These structures, therefore, represent intermediates along the catalytic pathway of PrmC and show how the (D/N)PPY motif can be used to select a wide variety substrates. Structures along the catalytic pathway of PrmC/HemK, an N5-glutamine AdoMet-dependent methyltransferase.,Schubert HL, Phillips JD, Hill CP Biochemistry. 2003 May 20;42(19):5592-9. PMID:12741815[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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