View source for 7pxw


==LPMO, expressed in E.coli, in complex with Cellotetraose==
<StructureSection load='7pxw' size='340' side='right'caption='[[7pxw]], [[Resolution|resolution]] 1.40&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[7pxw]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Panus_similis Panus similis]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=7PXW OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=7PXW 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]] 1.4&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=BGC:BETA-D-GLUCOSE'>BGC</scene>, <scene name='pdbligand=CL:CHLORIDE+ION'>CL</scene>, <scene name='pdbligand=CU:COPPER+(II)+ION'>CU</scene>, <scene name='pdbligand=PRD_900011:beta-cellotetraose'>PRD_900011</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=7pxw FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=7pxw OCA], [https://pdbe.org/7pxw PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=7pxw RCSB], [https://www.ebi.ac.uk/pdbsum/7pxw PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=7pxw ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/LP9A_PANSI LP9A_PANSI] Lytic polysaccharide monooxygenase (LPMO) that depolymerizes crystalline and amorphous polysaccharides via the oxidation of scissile alpha- or beta-(1-4)-glycosidic bonds, yielding C1 or C4 oxidation product (PubMed:26928935, PubMed:29057953, PubMed:32818374). Catalysis by LPMOs requires the reduction of the active-site copper from Cu(II) to Cu(I) by a reducing agent and H(2)O(2) or O(2) as a cosubstrate (PubMed:26928935, PubMed:29057953). Is able to cleave phosphoric acid swollen cellulose (PASC) in the presence of a reducing agent, yielding a range of cellooligosaccharides dominated by cellobiose and cellotriose (PubMed:26928935). Activity is less sensitive to the reducing agent potential when cleaving xylan, suggesting that distinct catalytic mechanisms exist for xylan and glucan cleavage (PubMed:29057953).<ref>PMID:26928935</ref> <ref>PMID:29057953</ref> <ref>PMID:32818374</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The recently discovered lytic polysaccharide monooxygenases (LPMOs) are Cu-containing enzymes capable of degrading polysaccharide substrates oxidatively. The generally accepted first step in the LPMO reaction is the reduction of the active-site metal ion from Cu(2+) to Cu(+). Here we have used a systematic diffraction data collection method to monitor structural changes in two AA9 LPMOs, one from Lentinus similis (LsAA9_A) and one from Thermoascus auranti-acus (TaAA9_A), as the active-site Cu is photoreduced in the X-ray beam. For LsAA9_A, the protein produced in two different recombinant systems was crystallized to probe the effect of post-translational modifications and different crystallization conditions on the active site and metal photoreduction. We can recommend that crystallographic studies of AA9 LPMOs wishing to address the Cu(2+) form use a total X-ray dose below 3 x 10(4) Gy, while the Cu(+) form can be attained using 1 x 10(6) Gy. In all cases, we observe the transition from a hexa-coordinated Cu site with two solvent-facing ligands to a T-shaped geometry with no exogenous ligands, and a clear increase of the theta(2) parameter and a decrease of the theta(3) parameter by averages of 9.2 degrees and 8.4 degrees , respectively, but also a slight increase in theta(T). Thus, the theta(2) and theta(3) parameters are helpful diagnostics for the oxidation state of the metal in a His-brace protein. On binding of cello-oligosaccharides to LsAA9_A, regardless of the production source, the theta(T) parameter increases, making the Cu site less planar, while the active-site Tyr-Cu distance decreases reproducibly for the Cu(2+) form. Thus, the theta(T) increase found on copper reduction may bring LsAA9_A closer to an oligosaccharide-bound state and contribute to the observed higher affinity of reduced LsAA9_A for cellulosic substrates.

Changes in active-site geometry on X-ray photoreduction of a lytic polysaccharide monooxygenase active-site copper and saccharide binding.,Tandrup T, Muderspach SJ, Banerjee S, Santoni G, Ipsen JO, Hernandez-Rollan C, Norholm MHH, Johansen KS, Meilleur F, Lo Leggio L IUCrJ. 2022 Aug 17;9(Pt 5):666-681. doi: 10.1107/S2052252522007175. eCollection , 2022 Sep 1. PMID:36071795<ref>PMID:36071795</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 7pxw" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Panus similis]]
[[Category: Banerjee S]]
[[Category: Ipsen J]]
[[Category: Johansen KS]]
[[Category: Lo Leggio L]]
[[Category: Muderspach SJ]]
[[Category: Norholm M]]
[[Category: Rollan CH]]
[[Category: Tandrup T]]