View source for 6tyr


==Crystal structure of Laccase from Thermus thermophilus HB27 with a close conformation of its beta-hairpin==
<StructureSection load='6tyr' size='340' side='right'caption='[[6tyr]], [[Resolution|resolution]] 1.81&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[6tyr]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Thermus_thermophilus_HB27 Thermus thermophilus HB27]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6TYR OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=6TYR 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]] 1.813&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CIT:CITRIC+ACID'>CIT</scene>, <scene name='pdbligand=CU:COPPER+(II)+ION'>CU</scene>, <scene name='pdbligand=GOL:GLYCEROL'>GOL</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=6tyr FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6tyr OCA], [https://pdbe.org/6tyr PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6tyr RCSB], [https://www.ebi.ac.uk/pdbsum/6tyr PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6tyr ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/Q72HW2_THET2 Q72HW2_THET2] 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The multi-copper oxidase from the hyper-thermophilic bacteria Thermus thermophilus (Tth-MCO), has been previously characterized and described as an example of a laccase with low catalytic properties, especially when it is compared with the activity of fungal laccases, but it is active at high temperatures. Structurally, Tth-MCO has a unique feature: a beta-hairpin near the T1Cu site, which is not present in any other laccases deposited at the PDB. This beta-hairpin has an expected crystallographic behavior in solvent-exposed areas of a crystallized protein: lack of electron density, high B-values and several crystalline contacts with neighboring crystallographic copies; however, its dynamical behavior in solution and its biological implications have not been described. Here, we describe four new Tth-MCO crystallographic structures, and the beta-hairpin behavior has been analyzed by molecular dynamics simulations, considering the effect of pH and temperature. The beta-hairpin new crystallographic conformations described here, together with their dynamics, were used to understand the pH-restrained laccase activity of Tth-MCO against substrates as syringaldazine. Remarkably, there are insertions in laccases from Thermus and Meiothermus genus, sharing the same position and a methionine-rich composition of the Tth-MCO beta-hairpin. This unique high methionine content of the Tth-MCO beta-hairpin is responsible to coordinate, Ag(+1) and Hg(+1) in oxidative conditions, but Cu(+1) and Cu(+2) are not coordinated in crystallographic experiments, regardless of the redox conditions; however, Ag(+1) addition does not affect Tth-MCO laccase activity against syringaldazine. Here, we propose that the pH-dependent beta-hairpin dynamical behavior could explain, at least in part, the inefficient laccase activity displayed by Tth-MCO in acidic pH values.

The beta-hairpin from the Thermus thermophilus HB27 laccase works as a pH-dependent switch to regulate laccase activity.,Miranda-Blancas R, Avelar M, Rodriguez-Arteaga A, Sinicropi A, Rudino-Pinera E J Struct Biol. 2021 Jun;213(2):107740. doi: 10.1016/j.jsb.2021.107740. Epub 2021 , May 5. PMID:33962016<ref>PMID:33962016</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 6tyr" style="background-color:#fffaf0;"></div>

==See Also==
*[[Laccase 3D structures|Laccase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Thermus thermophilus HB27]]
[[Category: Miranda-Blancas R]]
[[Category: Rudino-Pinera E]]