View source for 1xhk


==Crystal structure of M. jannaschii Lon proteolytic domain==
<StructureSection load='1xhk' size='340' side='right'caption='[[1xhk]], [[Resolution|resolution]] 1.90&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1xhk]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Methanocaldococcus_jannaschii Methanocaldococcus jannaschii]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1XHK OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1XHK 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]] 1.9&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=MES:2-(N-MORPHOLINO)-ETHANESULFONIC+ACID'>MES</scene>, <scene name='pdbligand=MSE:SELENOMETHIONINE'>MSE</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</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=1xhk FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1xhk OCA], [https://pdbe.org/1xhk PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1xhk RCSB], [https://www.ebi.ac.uk/pdbsum/1xhk PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1xhk ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/LONB_METJA LONB_METJA] ATP-dependent serine protease that mediates the selective degradation of mutant and abnormal proteins as well as certain short-lived regulatory proteins. Degrades polypeptides processively (By similarity).
== 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/xh/1xhk_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=1xhk ConSurf].
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== Publication Abstract from PubMed ==
ATP-dependent Lon proteases catalyze the degradation of various regulatory proteins and abnormal proteins within cells. Methanococcus jannaschii Lon (Mj-Lon) is a homologue of Escherichia coli Lon (Ec-Lon) but has two transmembrane helices within its N-terminal ATPase domain. We solved the crystal structure of the proteolytic domain of Mj-Lon using multiwavelength anomalous dispersion, refining it to 1.9-angstroms resolution. The structure displays an overall fold conserved in the proteolytic domain of Ec-Lon; however, the active site shows uniquely configured catalytic Ser-Lys-Asp residues that are not seen in Ec-Lon, which contains a catalytic dyad. In Mj-Lon, the C-terminal half of the beta4-alpha2 segment is an alpha-helix, whereas it is a beta-strand in Ec-Lon. Consequently, the configurations of the active sites differ due to the formation of a salt bridge between Asp-547 and Lys-593 in Mj-Lon. Moreover, unlike Ec-Lon, Mj-Lon has a buried cavity in the region of the active site containing three water molecules, one of which is hydrogen-bonded to catalytic Ser-550. The geometry and environment of the active site residues in Mj-Lon suggest that the charged Lys-593 assists in lowering the pK(a) of the Ser-550 hydroxyl group via its electrostatic potential, and the water in the cavity acts as a proton acceptor during catalysis. Extensive sequence alignment and comparison of the structures of the proteolytic domains clearly indicate that Lon proteases can be classified into two groups depending on active site configuration and the presence of DGPSA or (D/E)GDSA consensus sequences, as represented by Ec-Lon and Mj-Lon.

The active site of a lon protease from Methanococcus jannaschii distinctly differs from the canonical catalytic Dyad of Lon proteases.,Im YJ, Na Y, Kang GB, Rho SH, Kim MK, Lee JH, Chung CH, Eom SH J Biol Chem. 2004 Dec 17;279(51):53451-7. Epub 2004 Sep 28. PMID:15456757<ref>PMID:15456757</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 1xhk" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Methanocaldococcus jannaschii]]
[[Category: Chung CH]]
[[Category: Eom SH]]
[[Category: Im YJ]]
[[Category: Kang GB]]
[[Category: Kim M-K]]
[[Category: Lee JH]]
[[Category: Na Y]]
[[Category: Rho S-H]]