View source for 4o9a


==Crystal structure of Beta-ketothiolase (PhaA) from Ralstonia eutropha H16==
<StructureSection load='4o9a' size='340' side='right'caption='[[4o9a]], [[Resolution|resolution]] 1.52&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4o9a]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Cupriavidus_necator_H16 Cupriavidus necator H16]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4O9A OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4O9A 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]] 1.52&#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=4o9a FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4o9a OCA], [https://pdbe.org/4o9a PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4o9a RCSB], [https://www.ebi.ac.uk/pdbsum/4o9a PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4o9a ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/THIL_CUPNH THIL_CUPNH] Catalyzes the condensation of two acetyl-coA units to form acetoacetyl-CoA. Is involved in the biosynthesis of polyhydroxybutyrate (PHB), which is accumulated as an intracellular energy reserve material when cells grow under conditions of nutrient limitation. Also catalyzes the reverse reaction, i.e. the cleavage of acetoacetyl-CoA, and is therefore also involved in the reutilization of PHB.<ref>PMID:2670935</ref> <ref>PMID:2670936</ref> <ref>PMID:4198758</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
PhaA from Ralstonia eutropha (RePhaA) is the first enzyme in the polyhydroxyalbutyrate (PHB) biosynthetic pathway and catalyzes the condensation of two molecules of acetyl-CoA to acetoacetyl-CoA. To investigate the molecular mechanism underlying PHB biosynthesis, we determined the crystal structures of the RePhaA protein in apo- and CoA-bound forms. The RePhaA structure adopts the type II biosynthetic thiolase fold forming a tetramer by means of dimerization of two dimers. The crystal structure of RePhaA in complex with CoA revealed that the enzyme contained a unique Phe219 residue, resulting that the ADP moiety binds in somewhat different position compared with that bound in other thiolase enzymes. Our study provides structural insight into the substrate specificity of RePhaA. Results indicate the presence of a small pocket near the Cys88 covalent catalytic residue leading to the possibility of the enzyme to accommodate acetyl-CoA as a sole substrate instead of larger acyl-CoA molecules such as propionyl-CoA. Furthermore, the roles of key residues involved in substrate binding and enzyme catalysis were confirmed by site-directed mutagenesis.

Crystal structure and biochemical characterization of PhaA from Ralstonia eutropha, a polyhydroxyalkanoate-producing bacterium.,Kim EJ, Kim KJ Biochem Biophys Res Commun. 2014 Sep 12;452(1):124-9. doi:, 10.1016/j.bbrc.2014.08.074. Epub 2014 Aug 21. PMID:25152395<ref>PMID:25152395</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 4o9a" style="background-color:#fffaf0;"></div>

==See Also==
*[[Thiolase 3D structures|Thiolase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Cupriavidus necator H16]]
[[Category: Large Structures]]
[[Category: Kim EJ]]
[[Category: Kim J]]
[[Category: Kim KJ]]
[[Category: Kim S]]