1k5q

<StructureSection load='1k5q' size='340' side='right' caption='[[1k5q]], [[Resolution|resolution]] 2.34&Aring;' scene=''>

<table><tr><td colspan='2'>[[1k5q]] is a 2 chain structure with sequence from [http://en.wikipedia.org/wiki/"bacillus_coli"_migula_1895 "bacillus coli" migula 1895]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1K5Q OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1K5Q FirstGlance]. <br>

</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=CA:CALCIUM+ION'>CA</scene>, <scene name='pdbligand=PAC:2-PHENYLACETIC+ACID'>PAC</scene></td></tr>

<tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[1pnk|1pnk]], [[1pnl|1pnl]], [[1fxv|1fxv]], [[1jx9|1jx9]], [[1ai4|1ai4]], [[1ai5|1ai5]], [[1ai6|1ai6]], [[1ai7|1ai7]]</td></tr>

<tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">PAC ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=562 "Bacillus coli" Migula 1895])</td></tr>

<tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/Penicillin_amidase Penicillin amidase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.5.1.11 3.5.1.11] </span></td></tr>

<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1k5q FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1k5q OCA], [http://pdbe.org/1k5q PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=1k5q RCSB], [http://www.ebi.ac.uk/pdbsum/1k5q PDBsum]</span></td></tr>

<scriptWhenChecked>select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/k5/1k5q_consurf.spt"</scriptWhenChecked>

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== Publication Abstract from PubMed ==

Penicillin acylase catalyses the condensation of Calpha-substituted phenylacetic acids with beta-lactam nucleophiles, producing semi-synthetic beta-lactam antibiotics. For efficient synthesis a low affinity for phenylacetic acid and a high affinity for Calpha-substituted phenylacetic acid derivatives is desirable. We made three active site mutants, alphaF146Y, betaF24A and alphaF146Y/betaF24A, which all had a 2- to 10-fold higher affinity for Calpha-substituted compounds than wild-type enzyme. In addition, betaF24A had a 20-fold reduced affinity for phenylacetic acid. The molecular basis of the improved properties was investigated by X-ray crystallography. These studies showed that the higher affinity of alphaF146Y for (R)-alpha-methylphenylacetic acid can be explained by van der Waals interactions between alphaY146:OH and the Calpha-substituent. The betaF24A mutation causes an opening of the phenylacetic acid binding site. Only (R)-alpha-methylphenylacetic acid, but not phenylacetic acid, induces a conformation with the ligand tightly bound, explaining the weak binding of phenylacetic acid. A comparison of the betaF24A structure with other open conformations of penicillin acylase showed that betaF24 has a fixed position, whereas alphaF146 acts as a flexible lid on the binding site and reorients its position to achieve optimal substrate binding.

Structural and kinetic studies on ligand binding in wild-type and active-site mutants of penicillin acylase.,Alkema WB, Hensgens CM, Snijder HJ, Keizer E, Dijkstra BW, Janssen DB Protein Eng Des Sel. 2004 May;17(5):473-80. Epub 2004 Jul 14. PMID:15254299<ref>PMID:15254299</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 1k5q" style="background-color:#fffaf0;"></div>

== References ==

<references/>

[[Category: Bacillus coli migula 1895]]

[[Category: Penicillin amidase]]

[[Category: Dijkstra, B W]]

[[Category: Hensgens, C M.H]]

[[Category: Keizer, E]]

[[Category: Snijder, H J]]

[[Category: Ntn-hydrolase fold]]