View source for 1krb

==CRYSTAL STRUCTURE OF KLEBSIELLA AEROGENES UREASE, ITS APOENZYME AND TWO ACTIVE SITE MUTANTS==
<StructureSection load='1krb' size='340' side='right' caption='[[1krb]], [[Resolution|resolution]] 2.50&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1krb]] is a 3 chain structure with sequence from [http://en.wikipedia.org/wiki/Enterobacter_aerogenes Enterobacter aerogenes]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1KRB OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1KRB FirstGlance]. <br>
</td></tr><tr><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=NI:NICKEL+(II)+ION'>NI</scene><br>
<tr><td class="sblockLbl"><b>[[Non-Standard_Residue|NonStd Res:]]</b></td><td class="sblockDat"><scene name='pdbligand=KCX:LYSINE+NZ-CARBOXYLIC+ACID'>KCX</scene></td></tr>
<tr><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[1kau|1kau]]</td></tr>
<tr><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[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] </span></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=1krb FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1krb OCA], [http://www.rcsb.org/pdb/explore.do?structureId=1krb RCSB], [http://www.ebi.ac.uk/pdbsum/1krb 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/kr/1krb_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 ==
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.

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:8718850<ref>PMID:8718850</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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==See Also==
*[[Urease|Urease]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Enterobacter aerogenes]]
[[Category: Urease]]
[[Category: Jabri, E.]]
[[Category: Karplus, P A.]]
[[Category: Active site mutant]]
[[Category: Hydrolase]]
[[Category: Nickel metalloenzyme]]