View source for 7eny


==Crystal structure of hydroxysteroid dehydrogenase from Escherichia coli==
<StructureSection load='7eny' size='340' side='right'caption='[[7eny]], [[Resolution|resolution]] 2.70&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[7eny]] is a 8 chain structure with sequence from [https://en.wikipedia.org/wiki/Escherichia_coli_K-12 Escherichia coli K-12]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=7ENY OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=7ENY 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]] 2.703&#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=7eny FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=7eny OCA], [https://pdbe.org/7eny PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=7eny RCSB], [https://www.ebi.ac.uk/pdbsum/7eny PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=7eny ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/HDHA_ECOLI HDHA_ECOLI] 7-alpha-dehydroxylation of cholic acid, yielding deoxycholic acid and lithocholic acid, respectively. Highest affinity with taurochenodeoxycholic acid.
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
7alpha-Hydroxysteroid dehydrogenase (7alpha-HSDH) catalyzes the dehydrogenation of a hydroxyl group at the 7alpha position in steroid substrates using NAD(+) or NADP(+) as a co-factor. Although studies have determined the binary and ternary complex structures, detailed structural changes induced by ligand and co-factor binding remain unclear, because ligand-free structures are not yet available. Here, we present the crystal structure of apo 7alpha-HSDH from Escherichia coli (Eco-7alpha-HSDH) at 2.7 A resolution. We found that the apo form undergoes substantial conformational changes in the beta4-alpha4 loop, alpha7-alpha8 helices, and C-terminus loop among the four subunits comprising the tetramer. Furthermore, a comparison of the apo structure with the binary (NAD(+))-complex and ternary (NADH and 7-oxoglycochenodeoxycholic acid)-complex Eco-7alpha-HSDH structures revealed that only the ternary-complex structure has a fully closed conformation, whereas the binary-complex and apo structures have a semi-closed or open conformation. This open-to-closed transition forces several catalytically important residues (S146, Y159, and K163) into correct positions for catalysis. To confirm the catalytic activity, we used alcohol dehydrogenase for NAD(+) regeneration to allow efficient conversion of chenodeoxycholic acid to 7-ketolithocholic acid by Eco-7alpha-HSDH. These findings demonstrate that apo Eco-7alpha-HSDH exhibits intrinsically flexible characteristics with an open conformation. This structural information provides novel insight into the 7alpha-HSDH reaction mechanism.

Crystal structure of an apo 7alpha-hydroxysteroid dehydrogenase reveals key structural changes induced by substrate and co-factor binding.,Kim KH, Lee CW, Pardhe BD, Hwang J, Do H, Lee YM, Lee JH, Oh TJ J Steroid Biochem Mol Biol. 2021 Jun 23;212:105945. doi:, 10.1016/j.jsbmb.2021.105945. PMID:34171491<ref>PMID:34171491</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 7eny" style="background-color:#fffaf0;"></div>

==See Also==
*[[Hydroxysteroid dehydrogenase 3D structures|Hydroxysteroid dehydrogenase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Escherichia coli K-12]]
[[Category: Large Structures]]
[[Category: Do H]]
[[Category: Hwang J]]
[[Category: Kim K-H]]
[[Category: Lee CW]]
[[Category: Lee JH]]
[[Category: Lee YM]]
[[Category: Oh T-J]]
[[Category: Pardhe DP]]