View source for 1c7h


==CRYSTAL STRUCTURE OF A MUTANT R75A IN KETOSTEROID ISOMERASE FROM PSEDOMONAS PUTIDA BIOTYPE B==
<StructureSection load='1c7h' size='340' side='right'caption='[[1c7h]], [[Resolution|resolution]] 2.50&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1c7h]] is a 1 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=1C7H OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1C7H 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]] 2.5&#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=1c7h FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1c7h OCA], [https://pdbe.org/1c7h PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1c7h RCSB], [https://www.ebi.ac.uk/pdbsum/1c7h PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1c7h ProSAT]</span></td></tr>
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== Function ==
[https://www.uniprot.org/uniprot/SDIS_PSEPU SDIS_PSEPU] 
== 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/c7/1c7h_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=1c7h ConSurf].
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== Publication Abstract from PubMed ==
The aromatic residues Phe-54, Phe-82, and Trp-116 in the hydrophobic substrate-binding pocket of Delta(5)-3-ketosteroid isomerase from Pseudomonas putida biotype B have been characterized in their roles in steroid binding and catalysis. Kinetic and equilibrium binding analyses were carried out for the mutant enzymes with the substitutions Phe-54 --&gt; Ala or Leu, Phe-82 --&gt; Ala or Leu, and Trp-116 --&gt; Ala, Phe, or Tyr. The removal of their bulky, aromatic side chains at any of these three positions results in reduced k(cat), particularly when Phe-82 or Trp-116 is replaced by Ala. The results are consistent with the binding interactions of the aromatic residues with the bound steroid contributing to catalysis. All the mutations except the F82A mutation increase K(m); the F82A mutation decreases K(m) by ca. 3-fold, suggesting a possibility that the phenyl ring at position 82 might be unfavorable for substrate binding. The K(D) values for d-equilenin, an intermediate analogue, suggest that a space-filling hydrophobic side chain at position 54, a phenyl ring at position 82, and a nonpolar aromatic or small side chain at position 116 might be favorable for binding the reaction intermediate. In contrast to the increased K(D) for equilenin, the enzymes with any substitutions at positions 54 and 116 display a decreased K(D) for 19-nortestosterone, a product analogue, indicating that Phe-54 and Trp-116 might be unfavorable for product binding. The crystal structure of F82A determined to 2.1-A resolution reveals that Phe-82 is important for maintaining the active site geometry. Taken together, our results demonstrate that Phe-54, Phe-82, and Trp-116 contribute differentially to the stabilization of steroid species including substrate, intermediate, and product.

Roles of active site aromatic residues in catalysis by ketosteroid isomerase from Pseudomonas putida biotype B.,Kim DH, Nam GH, Jang DS, Choi G, Joo S, Kim JS, Oh BH, Choi KY Biochemistry. 1999 Oct 19;38(42):13810-9. PMID:10529226<ref>PMID:10529226</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 1c7h" style="background-color:#fffaf0;"></div>

==See Also==
*[[Ketosteroid Isomerase|Ketosteroid Isomerase]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Pseudomonas putida]]
[[Category: Choi G]]
[[Category: Choi KY]]
[[Category: Ha NC]]
[[Category: Jang DS]]
[[Category: Kim DH]]
[[Category: Nam GH]]
[[Category: Oh BH]]