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[[Image:1kra.gif|left|200px]]<br /><applet load="1kra" size="350" color="white" frame="true" align="right" spinBox="true"
caption="1kra, resolution 2.3&Aring;" />
'''CRYSTAL STRUCTURE OF KLEBSIELLA AEROGENES UREASE, ITS APOENZYME AND TWO ACTIVE SITE MUTANTS'''<br />


==Overview==
==CRYSTAL STRUCTURE OF KLEBSIELLA AEROGENES UREASE, ITS APOENZYME AND TWO ACTIVE SITE MUTANTS==
Urease from Klebsiella aerogenes [Jabri et al. (1995) Science 268, 998-1004] is an (alpha beta gamma)3 trimer with each alpha-subunit having an (alpha beta)8-barrel domain containing a binickel active center. Here we examine structure-function relations for urease in more detail through structural analysis of the urease apoenzyme at 2.3 A resolution and mutants of two key catalytic residues (H219A and H320A) at 2.5 A resolution. With the exception of the active site, in which a water molecule takes the place of the missing carbamate and nickel atoms, the structure of the apoenzyme is nearly identical to that of the holoenzyme, suggesting a high degree of preorganization which helps explain the tight binding of nickel. In the structure of H219A, the major change involves a conformational shift and ordering of the active site flap, but a small shift in the side chain of Asp alpha 221 could contribute to the lower activity of H219A. In the H320A structure, the catalytic water, primarily a Ni-2 ligand in the holoenzyme, shifts into a bridging position. This shift shows that the nickel ligation is rather sensitive to the environment and the change in ligation may contribute to the 10(5)-fold lower activity of H320A. In addition, these results show that urease is resilient to the loss of nickel ions and mutations. Analysis of the urease tertiary/quaternary structure suggests that the stability of this enzyme may be largely due to its burial of an unusually large fraction of its residues: 50% in the gamma-subunit, 30% in the beta-subunit, and 60% in the alpha-subunit.
<StructureSection load='1kra' size='340' side='right'caption='[[1kra]], [[Resolution|resolution]] 2.30&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1kra]] is a 3 chain structure with sequence from [https://en.wikipedia.org/wiki/Klebsiella_aerogenes Klebsiella aerogenes]. This structure supersedes the now removed PDB entry [http://oca.weizmann.ac.il/oca-bin/send-pdb?obs=1&id=3kau 3kau]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1KRA OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1KRA 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]] 2.3&#8491;</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=1kra FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1kra OCA], [https://pdbe.org/1kra PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1kra RCSB], [https://www.ebi.ac.uk/pdbsum/1kra PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1kra ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/URE3_KLEAE URE3_KLEAE]
== 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/kr/1kra_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=1kra ConSurf].
<div style="clear:both"></div>


==About this Structure==
==See Also==
1KRA is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Klebsiella_aerogenes Klebsiella aerogenes]. This structure supersedes the now removed PDB entry 3KAU. Active as [http://en.wikipedia.org/wiki/Urease Urease], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.5.1.5 3.5.1.5] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1KRA OCA].
*[[Urease 3D structures|Urease 3D structures]]
 
__TOC__
==Reference==
</StructureSection>
Structures of the Klebsiella aerogenes urease apoenzyme and two active-site mutants., Jabri E, Karplus PA, Biochemistry. 1996 Aug 20;35(33):10616-26. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=8718850 8718850]
[[Category: Klebsiella aerogenes]]
[[Category: Klebsiella aerogenes]]
[[Category: Protein complex]]
[[Category: Large Structures]]
[[Category: Urease]]
[[Category: Jabri E]]
[[Category: Jabri, E.]]
[[Category: Karplus PA]]
[[Category: Karplus, P A.]]
[[Category: apoenzyme]]
[[Category: nickel metalloenzyme]]
 
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Retrieved from "https://proteopedia.org/1kra"