View source for 4q8l


==Crystal structure of polysacchride lyase family 18 aly-SJ02 r-CATD==
<StructureSection load='4q8l' size='340' side='right'caption='[[4q8l]], [[Resolution|resolution]] 2.10&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4q8l]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Pseudoalteromonas_sp._SM0524 Pseudoalteromonas sp. SM0524]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4Q8L OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4Q8L 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]] 2.099&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CA:CALCIUM+ION'>CA</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=4q8l FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4q8l OCA], [https://pdbe.org/4q8l PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4q8l RCSB], [https://www.ebi.ac.uk/pdbsum/4q8l PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4q8l ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/B2LME8_9GAMM B2LME8_9GAMM] 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Bacterial alginate lyases, which are members of several polysaccharide lyase (PL) families, have important biological roles and biotechnological applications. The mechanisms for maturation, substrate recognition, and catalysis of PL18 alginate lyases are still largely unknown. A PL18 alginate lyase, aly-SJ02, from Pseudoalteromonas sp. 0524 displays a beta-jelly roll scaffold. Structural and biochemical analyses indicated that the N-terminal extension in the aly-SJ02 precursor may act as an intramolecular chaperone to mediate the correct folding of the catalytic domain. Molecular dynamics simulations and mutational assays suggested that the lid loops over the aly-SJ02 active center serve as a gate for substrate entry. Molecular docking and site-directed mutations revealed that certain conserved residues at the active center, especially those at subsites +1 and +2, are crucial for substrate recognition. Tyr(353) may function as both a catalytic base and acid. Based on our results, a model for the catalysis of aly-SJ02 in alginate depolymerization is proposed. Moreover, although bacterial alginate lyases from families PL5, 7, 15, and 18 adopt distinct scaffolds, they share the same conformation of catalytic residues, reflecting their convergent evolution. Our results provide the foremost insight into the mechanisms of maturation, substrate recognition, and catalysis of a PL18 alginate lyase.

Molecular insight into the role of the N-terminal extension in the maturation, substrate recognition, and catalysis of a bacterial alginate lyase from polysaccharide lyase family 18.,Dong S, Wei TD, Chen XL, Li CY, Wang P, Xie BB, Qin QL, Zhang XY, Pang XH, Zhou BC, Zhang YZ J Biol Chem. 2014 Oct 24;289(43):29558-69. doi: 10.1074/jbc.M114.584573. Epub, 2014 Sep 10. PMID:25210041<ref>PMID:25210041</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 4q8l" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Pseudoalteromonas sp. SM0524]]
[[Category: Dong S]]
[[Category: Li CY]]
[[Category: Zhang YZ]]