1gkf: Difference between revisions

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[[Image:1gkf.gif|left|200px]]


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==Crystal structures of penicillin acylase enzyme-substrate complexes: Structural insights into the catalytic mechanism==
The line below this paragraph, containing "STRUCTURE_1gkf", creates the "Structure Box" on the page.
<StructureSection load='1gkf' size='340' side='right'caption='[[1gkf]], [[Resolution|resolution]] 1.41&Aring;' scene=''>
You may change the PDB parameter (which sets the PDB file loaded into the applet)
== Structural highlights ==
or the SCENE parameter (which sets the initial scene displayed when the page is loaded),
<table><tr><td colspan='2'>[[1gkf]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1GKF OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1GKF FirstGlance]. <br>
or leave the SCENE parameter empty for the default display.
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 1.41&#8491;</td></tr>
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<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CA:CALCIUM+ION'>CA</scene>, <scene name='pdbligand=EDO:1,2-ETHANEDIOL'>EDO</scene>, <scene name='pdbligand=SME:METHIONINE+SULFOXIDE'>SME</scene></td></tr>
{{STRUCTURE_1gkf|  PDB=1gkf |  SCENE= }}
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=1gkf FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1gkf OCA], [https://pdbe.org/1gkf PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1gkf RCSB], [https://www.ebi.ac.uk/pdbsum/1gkf PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1gkf ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/PAC_ECOLX PAC_ECOLX]
== 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/gk/1gkf_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=1gkf ConSurf].
<div style="clear:both"></div>


'''CRYSTAL STRUCTURES OF PENICILLIN ACYLASE ENZYME-SUBSTRATE COMPLEXES: STRUCTURAL INSIGHTS INTO THE CATALYTIC MECHANISM'''
==See Also==
 
*[[Penicillin acylase|Penicillin acylase]]
 
__TOC__
==Overview==
</StructureSection>
The crystal structure of penicillin G acylase from Escherichia coli has been determined to a resolution of 1.3 A from a crystal form grown in the presence of ethylene glycol. To study aspects of the substrate specificity and catalytic mechanism of this key biotechnological enzyme, mutants were made to generate inactive protein useful for producing enzyme-substrate complexes. Owing to the intimate association of enzyme activity and precursor processing in this protein family (the Ntn hydrolases), most attempts to alter active-site residues lead to processing defects. Mutation of the invariant residue Arg B263 results in the accumulation of a protein precursor form. However, the mutation of Asn B241, a residue implicated in stabilisation of the tetrahedral intermediate during catalysis, inactivates the enzyme but does not prevent autocatalytic processing or the ability to bind substrates. The crystal structure of the Asn B241 Ala oxyanion hole mutant enzyme has been determined in its native form and in complex with penicillin G and penicillin G sulphoxide. We show that Asn B241 has an important role in maintaining the active site geometry and in productive substrate binding, hence the structure of the mutant protein is a poor model for the Michaelis complex. For this reason, we subsequently solved the structure of the wild-type protein in complex with the slowly processed substrate penicillin G sulphoxide. Analysis of this structure suggests that the reaction mechanism proceeds via direct nucleophilic attack of Ser B1 on the scissile amide and not as previously proposed via a tightly H-bonded water molecule acting as a "virtual" base.
 
==About this Structure==
1GKF is a [[Protein complex]] structure of sequences from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1GKF OCA].
 
==Reference==
Crystal structures of penicillin acylase enzyme-substrate complexes: structural insights into the catalytic mechanism., McVey CE, Walsh MA, Dodson GG, Wilson KS, Brannigan JA, J Mol Biol. 2001 Oct 12;313(1):139-50. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/11601852 11601852]
[[Category: Escherichia coli]]
[[Category: Escherichia coli]]
[[Category: Penicillin amidase]]
[[Category: Large Structures]]
[[Category: Protein complex]]
[[Category: Brannigan JA]]
[[Category: Brannigan, J A.]]
[[Category: Dodson GG]]
[[Category: Dodson, G G.]]
[[Category: McVey CE]]
[[Category: Mcvey, C E.]]
[[Category: Walsh MA]]
[[Category: Walsh, M A.]]
[[Category: Wilson KS]]
[[Category: Wilson, K S.]]
[[Category: Antibiotic resistance]]
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Fri May  2 17:41:22 2008''

Latest revision as of 14:22, 27 March 2024

Crystal structures of penicillin acylase enzyme-substrate complexes: Structural insights into the catalytic mechanismCrystal structures of penicillin acylase enzyme-substrate complexes: Structural insights into the catalytic mechanism

Structural highlights

1gkf is a 2 chain structure with sequence from Escherichia coli. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:X-ray diffraction, Resolution 1.41Å
Ligands:, ,
Resources:FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

PAC_ECOLX

Evolutionary Conservation

Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.

See Also

1gkf, resolution 1.41Å

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