1xys

<table><tr><td colspan='2'>[[1xys]] is a 2 chain structure with sequence from [http://en.wikipedia.org/wiki/"cellvibrio_cellulosa"_nagy_et_al._2002 "cellvibrio cellulosa" nagy et al. 2002]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1XYS OCA]. For a <b>guided tour on the structure components</b> use [http://proteopedia.org/fgij/fg.htm?mol=1XYS FirstGlance]. <br>

</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='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">TRUNCATED XYNA (CODONS 264-611) ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=155077 "Cellvibrio cellulosa" Nagy et al. 2002])</td></tr>

<tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/Endo-1,4-beta-xylanase Endo-1,4-beta-xylanase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.2.1.8 3.2.1.8] </span></td></tr>

<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://proteopedia.org/fgij/fg.htm?mol=1xys FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1xys OCA], [http://pdbe.org/1xys PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=1xys RCSB], [http://www.ebi.ac.uk/pdbsum/1xys PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=1xys ProSAT]</span></td></tr>

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== Publication Abstract from PubMed ==

BACKGROUND: Sequence alignment suggests that xylanases evolved from two ancestral proteins and therefore can be grouped into two families, designated F and G. Family F enzymes show no sequence similarity with any known structure and their architecture is unknown. Studies of an inactive enzyme-substrate complex will help to elucidate the structural basis of binding and catalysis in the family F xylanases. RESULTS: We have therefore determined the crystal structure of the catalytic domain of a family F enzyme, Pseudomonas fluorescens subsp. cellulosa xylanase A, at 2.5 A resolution and a crystallographic R-factor of 0.20. The structure was solved using an engineered catalytic core in which the nucleophilic glutamate was replaced by a cysteine. As expected, this yielded both high-quality mercurial derivatives and an inactive enzyme which enabled the preparation of the inactive enzyme-substrate complex in the crystal. We show that family F xylanases are eight-fold alpha/beta-barrels (TIM barrels) with two active-site glutamates, one of which is the nucleophile and the other the acid-base. Xylopentaose binds to five subsites A-E with the cleaved bond between subsites D and E. Ca2+ binding, remote from the active-site glutamates, stabilizes the structure and may be involved in the binding of extended substrates. CONCLUSIONS: The architecture of P. fluorescens subsp. cellulosa has been determined crystallographically to be a commonly occurring enzyme fold, the eight-fold alpha/beta-barrel. Xylopentaose binds across the carboxy-terminal end of the alpha/beta-barrel in an active-site cleft which contains the two catalytic glutamates.

Structure of the catalytic core of the family F xylanase from Pseudomonas fluorescens and identification of the xylopentaose-binding sites.,Harris GW, Jenkins JA, Connerton I, Cummings N, Lo Leggio L, Scott M, Hazlewood GP, Laurie JI, Gilbert HJ, Pickersgill RW Structure. 1994 Nov 15;2(11):1107-16. PMID:7881909<ref>PMID:7881909</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 1xys" style="background-color:#fffaf0;"></div>

== References ==

<references/>

[[Category: Cellvibrio cellulosa nagy et al. 2002]]

[[Category: Endo-1,4-beta-xylanase]]

[[Category: Connerton, I]]

[[Category: Harris, G W]]

[[Category: Jenkins, J A]]

[[Category: Pickersgill, R W]]

[[Category: Hydrolase]]