View source for 3ce6


==Crystal structure of Mycobacterium tuberculosis S-adenosyl-L-homocysteine hydrolase in ternary complex with NAD and adenosine==
<StructureSection load='3ce6' size='340' side='right'caption='[[3ce6]], [[Resolution|resolution]] 1.60&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[3ce6]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Myctu Myctu]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3CE6 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=3CE6 FirstGlance]. <br>
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=ADN:ADENOSINE'>ADN</scene>, <scene name='pdbligand=NAD:NICOTINAMIDE-ADENINE-DINUCLEOTIDE'>NAD</scene></td></tr>
<tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat"><div style='overflow: auto; max-height: 3em;'>[[1li4|1li4]], [[2ziz|2ziz]], [[2zj0|2zj0]], [[2zj1|2zj1]]</div></td></tr>
<tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">ahcY, sahH, Rv3248c, MT3346,  MTCY20B11.23c ([https://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=83332 MYCTU])</td></tr>
<tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[https://en.wikipedia.org/wiki/Adenosylhomocysteinase Adenosylhomocysteinase], with EC number [https://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.3.1.1 3.3.1.1] </span></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=3ce6 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3ce6 OCA], [https://pdbe.org/3ce6 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=3ce6 RCSB], [https://www.ebi.ac.uk/pdbsum/3ce6 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=3ce6 ProSAT]</span></td></tr>
</table>
== Function ==
[[https://www.uniprot.org/uniprot/SAHH_MYCTU SAHH_MYCTU]] May play a key role in the regulation of the intracellular concentration of adenosylhomocysteine (By similarity).[HAMAP-Rule:MF_00563] 
== 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/ce/3ce6_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=3ce6 ConSurf].
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== Publication Abstract from PubMed ==
S-adenosylhomocysteine hydrolase (SAHH) is a ubiquitous enzyme that plays a central role in methylation-based processes by maintaining the intracellular balance between S-adenosylhomocysteine (SAH) and S-adenosylmethionine. We report the first prokaryotic crystal structure of SAHH, from Mycobacterium tuberculosis (Mtb), in complex with adenosine (ADO) and nicotinamide adenine dinucleotide. Structures of complexes with three inhibitors are also reported: 3'-keto aristeromycin (ARI), 2-fluoroadenosine, and 3-deazaadenosine. The ARI complex is the first reported structure of SAHH complexed with this inhibitor, and confirms the oxidation of the 3' hydroxyl to a planar keto group, consistent with its prediction as a mechanism-based inhibitor. We demonstrate the in vivo enzyme inhibition activity of the three inhibitors and also show that 2-fluoradenosine has bactericidal activity. While most of the residues lining the ADO-binding pocket are identical between Mtb and human SAHH, less is known about the binding mode of the homocysteine (HCY) appendage of the full substrate. We report the 2.0 A resolution structure of the complex of SAHH cocrystallized with SAH. The most striking change in the structure is that binding of HCY forces a rotation of His363 around the backbone to flip out of contact with the 5' hydroxyl of the ADO and opens access to a nearby channel that leads to the surface. This complex suggests that His363 acts as a switch that opens up to permit binding of substrate, then closes down after release of the cleaved HCY. Differences in the entrance to this access channel between human and Mtb SAHH are identified.

Crystal structures of Mycobacterium tuberculosis S-adenosyl-L-homocysteine hydrolase in ternary complex with substrate and inhibitors.,Reddy MC, Kuppan G, Shetty ND, Owen JL, Ioerger TR, Sacchettini JC Protein Sci. 2008 Dec;17(12):2134-44. Epub 2008 Sep 24. PMID:18815415<ref>PMID:18815415</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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==See Also==
*[[S-adenosylhomocysteine hydrolase|S-adenosylhomocysteine hydrolase]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Adenosylhomocysteinase]]
[[Category: Large Structures]]
[[Category: Myctu]]
[[Category: Gokulan, K]]
[[Category: Ioerger, T R]]
[[Category: Owen, J L]]
[[Category: Reddy, M C.M]]
[[Category: Sacchettini, J C]]
[[Category: Shetty, N D]]
[[Category: 37 amino acid insertional region]]
[[Category: Dimer of dimer]]
[[Category: Hydrolase]]
[[Category: Nad binding domain]]
[[Category: One-carbon metabolism]]
[[Category: Protein-substrate complex]]