View source for 4hnc


==P. putida C92S/K166C/C264S mandelate racemase co-crystallized with benzilic acid==
<StructureSection load='4hnc' size='340' side='right'caption='[[4hnc]], [[Resolution|resolution]] 1.89&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4hnc]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Pseudomonas_putida Pseudomonas putida]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4HNC OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4HNC 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]] 1.889&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=0UT:HYDROXY(DIPHENYL)ACETIC+ACID'>0UT</scene>, <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</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=4hnc FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4hnc OCA], [https://pdbe.org/4hnc PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4hnc RCSB], [https://www.ebi.ac.uk/pdbsum/4hnc PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4hnc ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/MANR_PSEPU MANR_PSEPU] 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Mandelate racemase (MR) from Pseudomonas putida catalyzes the Mg(2+)-dependent 1,1-proton transfer that interconverts the enantiomers of mandelate. Because trifluorolactate is also a substrate of MR, we anticipated that replacing the phenyl rings of the competitive, substrate-product analogue inhibitor benzilate (Ki = 0.7 mM) with trifluoromethyl groups might furnish an inhibitor. Surprisingly, the substrate-product analogue 3,3,3-trifluoro-2-hydroxy-2-(trifluoromethyl)propanoate (TFHTP) was a potent competitive inhibitor [Ki = 27 +/- 4 muM; cf. Km = 1.2 mM for both (R)-mandelate and (R)-trifluorolactate]. To understand the origins of this high binding affinity, we determined the X-ray crystal structure of the MR-TFHTP complex to 1.68 A resolution. Rather than chelating the active site Mg(2+) with its glycolate moiety, like other ground state analogues, TFHTP exhibited a novel binding mode with the two trifluoromethyl groups closely packed against the 20s loop and the carboxylate bridging the two active site Bronsted acid-base catalysts Lys 166 and His 297. Recognizing that positioning a carboxylate between the Bronsted acid-base catalysts could yield an inhibitor, we showed that tartronate was a competitive inhibitor of MR (Ki = 1.8 +/- 0.1 mM). The X-ray crystal structure of the MR-tartronate complex (1.80 A resolution) revealed that the glycolate moiety of tartronate chelated the Mg(2+) and that the carboxylate bridged Lys 166 and His 297. Models of tartronate in monomers A and B of the crystal structure mimicked the binding orientations of (S)-mandelate and that anticipated for (R)-mandelate, respectively. For the latter monomer, the 20s loop appeared to be disordered, as it also did in the X-ray structure of the MR triple mutant (C92S/C264S/K166C) complexed with benzilate, which was determined to 1.89 A resolution. These observations indicate that the 20s loop likely undergoes a significant conformational change upon binding (R)-mandelate. In general, our observations suggest that inhibitors of other enolase superfamily enzymes may be designed to capitalize on the recognition of the active site Bronsted acid-base catalysts as binding determinants.

Potent inhibition of mandelate racemase by a fluorinated substrate-product analogue with a novel binding mode.,Nagar M, Lietzan AD, St Maurice M, Bearne SL Biochemistry. 2014 Feb 25;53(7):1169-78. doi: 10.1021/bi401703h. Epub 2014 Feb, 10. PMID:24472022<ref>PMID:24472022</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 4hnc" style="background-color:#fffaf0;"></div>

==See Also==
*[[Mandelate racemase|Mandelate racemase]]
== References ==
<references/>
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</StructureSection>
[[Category: Large Structures]]
[[Category: Pseudomonas putida]]
[[Category: Lietzan AD]]
[[Category: StMaurice M]]