1cg4: Difference between revisions

New page: left|200px<br /><applet load="1cg4" size="450" color="white" frame="true" align="right" spinBox="true" caption="1cg4, resolution 2.5Å" /> '''STRUCTURE OF THE MUTA...
 
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'''STRUCTURE OF THE MUTANT (R303L) OF ADENYLOSUCCINATE SYNTHETASE FROM E. COLI COMPLEXED WITH, GDP, 6-PHOSPHORYL-IMP, AND MG2+'''<br />


==Overview==
==STRUCTURE OF THE MUTANT (R303L) OF ADENYLOSUCCINATE SYNTHETASE FROM E. COLI COMPLEXED WITH, GDP, 6-PHOSPHORYL-IMP, AND MG2+==
Asp13 and His41 are essential residues of adenylosuccinate synthetase, putatively catalyzing the formation of adenylosuccinate from an, intermediate of 6-phosphoryl-IMP. Wild-type adenylosuccinate synthetase, and three mutant synthetases (Arg143 --&gt; Leu, Lys16 --&gt; Gln, and Arg303, --&gt; Leu) from Eschericha coli have been crystallized in the presence of, IMP, hadacidin (an analogue of L-aspartate), Mg2+, and GTP. The active, site of each complex contains 6-phosphoryl-IMP, Mg2+, GDP, and hadacidin, except for the Arg303 --&gt; Leu mutant, which does not bind hadacidin. In, response to the formation of 6-phosphoryl-IMP, Asp13 enters the inner, coordination sphere of the active site Mg2+. His41 hydrogen bonds with, 6-phosphoryl-IMP, except in the Arg303 --&gt; Leu complex, where it remains, bound to the guanine nucleotide. Hence, recognition of the active site, Mg2+ by Asp13 evidently occurs after the formation of 6-phosphoryl-IMP, but recognition of the intermediate by His41 may require the association, of L-aspartate with the active site. Structures reported here support a, mechanism in which Asp13 and His41 act as the catalytic base and acid, respectively, in the formation of 6-phosphoryl-IMP, and then act together, as catalytic acids in the subsequent formation of adenylosuccinate.
<StructureSection load='1cg4' size='340' side='right'caption='[[1cg4]], [[Resolution|resolution]] 2.50&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1cg4]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Escherichia_coli_K-12 Escherichia coli K-12]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1CG4 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1CG4 FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 2.5&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=GDP:GUANOSINE-5-DIPHOSPHATE'>GDP</scene>, <scene name='pdbligand=IMO:6-O-PHOSPHORYL+INOSINE+MONOPHOSPHATE'>IMO</scene>, <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene></td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=1cg4 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1cg4 OCA], [https://pdbe.org/1cg4 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1cg4 RCSB], [https://www.ebi.ac.uk/pdbsum/1cg4 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1cg4 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/PURA_ECOLI PURA_ECOLI] Plays an important role in the de novo pathway of purine nucleotide biosynthesis. Catalyzes the first committed step in the biosynthesis of AMP from IMP (By similarity).[HAMAP-Rule:MF_00011]
== 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/cg/1cg4_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/main_output.php?pdb_ID=1cg4 ConSurf].
<div style="clear:both"></div>
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Asp13 and His41 are essential residues of adenylosuccinate synthetase, putatively catalyzing the formation of adenylosuccinate from an intermediate of 6-phosphoryl-IMP. Wild-type adenylosuccinate synthetase and three mutant synthetases (Arg143 --&gt; Leu, Lys16 --&gt; Gln, and Arg303 --&gt; Leu) from Eschericha coli have been crystallized in the presence of IMP, hadacidin (an analogue of L-aspartate), Mg2+, and GTP. The active site of each complex contains 6-phosphoryl-IMP, Mg2+, GDP, and hadacidin, except for the Arg303 --&gt; Leu mutant, which does not bind hadacidin. In response to the formation of 6-phosphoryl-IMP, Asp13 enters the inner coordination sphere of the active site Mg2+. His41 hydrogen bonds with 6-phosphoryl-IMP, except in the Arg303 --&gt; Leu complex, where it remains bound to the guanine nucleotide. Hence, recognition of the active site Mg2+ by Asp13 evidently occurs after the formation of 6-phosphoryl-IMP, but recognition of the intermediate by His41 may require the association of L-aspartate with the active site. Structures reported here support a mechanism in which Asp13 and His41 act as the catalytic base and acid, respectively, in the formation of 6-phosphoryl-IMP, and then act together as catalytic acids in the subsequent formation of adenylosuccinate.


==About this Structure==
Mechanistic implications from crystalline complexes of wild-type and mutant adenylosuccinate synthetases from Escherichia coli.,Choe JY, Poland BW, Fromm HJ, Honzatko RB Biochemistry. 1999 May 25;38(21):6953-61. PMID:10346917<ref>PMID:10346917</ref>
1CG4 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with MG, IMO and GDP as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Adenylosuccinate_synthase Adenylosuccinate synthase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=6.3.4.4 6.3.4.4] Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1CG4 OCA].


==Reference==
From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
Mechanistic implications from crystalline complexes of wild-type and mutant adenylosuccinate synthetases from Escherichia coli., Choe JY, Poland BW, Fromm HJ, Honzatko RB, Biochemistry. 1999 May 25;38(21):6953-61. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=10346917 10346917]
</div>
[[Category: Adenylosuccinate synthase]]
<div class="pdbe-citations 1cg4" style="background-color:#fffaf0;"></div>
[[Category: Escherichia coli]]
[[Category: Single protein]]
[[Category: Choe, J.Y.]]
[[Category: Fromm, H.]]
[[Category: Honzatko, R.]]
[[Category: Poland, B.W.]]
[[Category: GDP]]
[[Category: IMO]]
[[Category: MG]]
[[Category: 6-phosporyl-imp]]
[[Category: gtp-hydrolysing enzymes]]
[[Category: ligase]]
[[Category: purine 2 nucleotide biosynthesis]]


''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Tue Nov 20 12:25:37 2007''
==See Also==
*[[Adenylosuccinate synthetase 3D structures|Adenylosuccinate synthetase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Escherichia coli K-12]]
[[Category: Large Structures]]
[[Category: Choe JY]]
[[Category: Fromm H]]
[[Category: Honzatko R]]
[[Category: Poland BW]]

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