View source for 1p50


==Transition state structure of an Arginine Kinase mutant==
<StructureSection load='1p50' size='340' side='right'caption='[[1p50]], [[Resolution|resolution]] 2.80&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1p50]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Limulus_polyphemus Limulus polyphemus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1P50 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1P50 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]] 2.8&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=ADP:ADENOSINE-5-DIPHOSPHATE'>ADP</scene>, <scene name='pdbligand=ARG:ARGININE'>ARG</scene>, <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene>, <scene name='pdbligand=NO3:NITRATE+ION'>NO3</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=1p50 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1p50 OCA], [https://pdbe.org/1p50 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1p50 RCSB], [https://www.ebi.ac.uk/pdbsum/1p50 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1p50 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/KARG_LIMPO KARG_LIMPO] 
== 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/p5/1p50_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=1p50 ConSurf].
<div style="clear:both"></div>
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Arginine kinase is a member of the phosphagen kinase family that includes creatine kinase and likely shares a common reaction mechanism in catalyzing the buffering of cellular ATP energy levels. Abstraction of a proton from the substrate guanidinium by a catalytic base has long been thought to be an early mechanistic step. The structure of arginine kinase as a transition state analog complex (Zhou, G., Somasundaram, T., Blanc, E., Parthasarathy, G., Ellington, W. R., and Chapman, M. S. (1998) Proc. Natl. Acad. Sci. U. S. A. 95, 8449-8454) showed that Glu-225 and Glu-314 were the only potential catalytic residues contacting the phosphorylated nitrogen. In the present study, these residues were changed to Asp, Gln, and Val or Ala in several single and multisite mutant enzymes. These mutations had little impact on the substrate binding constants. The effect upon activity varied with reductions in kcat between 3000-fold and less than 2-fold. The retention of significant activity in some mutants contrasts with published studies of homologues and suggests that acid-base catalysis by these residues may enhance the rate but is not absolutely essential. Crystal structures of mutant enzymes E314D at 1.9 A and E225Q at 2.8 A resolution showed that the precise alignment of substrates is subtly distorted. Thus, pre-ordering of substrates might be just as important as acid-base chemistry, electrostatics, or other potential effects in the modest impact of these residues upon catalysis.

The putative catalytic bases have, at most, an accessory role in the mechanism of arginine kinase.,Pruett PS, Azzi A, Clark SA, Yousef MS, Gattis JL, Somasundaram T, Ellington WR, Chapman MS J Biol Chem. 2003 Jul 18;278(29):26952-7. Epub 2003 May 5. PMID:12732621<ref>PMID:12732621</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 1p50" style="background-color:#fffaf0;"></div>

==See Also==
*[[Arginine kinase 3D structures|Arginine kinase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Limulus polyphemus]]
[[Category: Azzi A]]
[[Category: Chapman MS]]
[[Category: Clark SA]]
[[Category: Ellington WR]]
[[Category: Gattis JL]]
[[Category: Pruett PS]]
[[Category: Somasundarum T]]
[[Category: Yousef MS]]