View source for 1ch8


==STRUCTURE OF ADENYLOSUCCINATE SYNTHETASE FROM E. COLI COMPLEXED WITH A STRINGENT EFFECTOR, PPG2':3'P==
<StructureSection load='1ch8' size='340' side='right'caption='[[1ch8]], [[Resolution|resolution]] 2.50&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1ch8]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Ecoli Ecoli]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1CH8 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1CH8 FirstGlance]. <br>
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=GPX:GUANOSINE+5-DIPHOSPHATE+2 3-CYCLIC+MONOPHOSPHATE'>GPX</scene>, <scene name='pdbligand=HDA:HADACIDIN'>HDA</scene>, <scene name='pdbligand=IMP:INOSINIC+ACID'>IMP</scene>, <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene>, <scene name='pdbligand=NO3:NITRATE+ION'>NO3</scene></td></tr>
<tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[https://en.wikipedia.org/wiki/Adenylosuccinate_synthase Adenylosuccinate synthase], with EC number [https://www.brenda-enzymes.info/php/result_flat.php4?ecno=6.3.4.4 6.3.4.4] </span></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=1ch8 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1ch8 OCA], [https://pdbe.org/1ch8 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1ch8 RCSB], [https://www.ebi.ac.uk/pdbsum/1ch8 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1ch8 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/ch/1ch8_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=1ch8 ConSurf].
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== Publication Abstract from PubMed ==
Guanosine 5'-diphosphate 3'-diphosphate (ppGpp), a pleiotropic effector of the stringent response, potently inhibits adenylosuccinate synthetase from Escherichia coli as an allosteric effector and/or as a competitive inhibitor with respect to GTP. Crystals of the synthetase grown in the presence of IMP, hadacidin, NO3-, and Mg2+, then soaked with ppGpp, reveal electron density at the GTP pocket which is consistent with guanosine 5'-diphosphate 2':3'-cyclic monophosphate. Unlike ligand complexes of the synthetase involving IMP and GDP, the coordination of Mg2+ in this complex is octahedral with the side chain of Asp13 in the inner sphere of the cation. The cyclic phosphoryl group interacts directly with the side chain of Lys49 and indirectly through bridging water molecules with the side chains of Asn295 and Arg305. The synthetase either directly facilitates the formation of the cyclic nucleotide or scavenges trace amounts of the cyclic nucleotide from solution. Regardless of its mode of generation, the cyclic nucleotide binds far more tightly to the active site than does ppGpp. Conceivably, synthetase activity in vivo during the stringent response may be sensitive to the relative concentrations of several effectors, which together exercise precise control over the de novo synthesis of AMP.

Effectors of the stringent response target the active site of Escherichia coli adenylosuccinate synthetase.,Hou Z, Cashel M, Fromm HJ, Honzatko RB J Biol Chem. 1999 Jun 18;274(25):17505-10. PMID:10364182<ref>PMID:10364182</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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<div class="pdbe-citations 1ch8" style="background-color:#fffaf0;"></div>

==See Also==
*[[Adenylosuccinate synthetase 3D structures|Adenylosuccinate synthetase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Adenylosuccinate synthase]]
[[Category: Ecoli]]
[[Category: Large Structures]]
[[Category: Cashel, M]]
[[Category: Fromm, H J]]
[[Category: Honzatko, R B]]
[[Category: Hou, Z]]
[[Category: Adenylosuccinate synthetase]]
[[Category: Gtp-hydrolysing enzyme]]
[[Category: Ligase]]
[[Category: Ppg2':3'p]]
[[Category: Ppgpp]]
[[Category: Purine 2 nucleotide biosynthesis]]
[[Category: Stringent effector]]