View source for 1bxc


==XYLOSE ISOMERASE FROM THERMUS CALDOPHILUS==
<StructureSection load='1bxc' size='340' side='right'caption='[[1bxc]], [[Resolution|resolution]] 2.30&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1bxc]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Thermus_caldophilus Thermus caldophilus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1BXC OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1BXC 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]] 2.3&#8491;</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=1bxc FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1bxc OCA], [https://pdbe.org/1bxc PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1bxc RCSB], [https://www.ebi.ac.uk/pdbsum/1bxc PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1bxc ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/XYLA_THECA XYLA_THECA] 
== 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/bx/1bxc_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=1bxc ConSurf].
<div style="clear:both"></div>
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The crystal structures of highly thermostable xylose isomerases from Thermus thermophilus (TthXI) and Thermus caldophilus (TcaXI), both with the optimum reaction temperature of 90 degrees C, have been determined by X-ray crystallography. The model of TcaXI has been refined to an R-factor of 17.8 % for data extending to 2.3 A and that of TthXI to 17.1 % for data extending to 2.2 A. The tetrameric arrangement of subunits characterized by the 222-symmetry and the tertiary fold of each subunit in both TcaXI and TthXI are basically the same as in other xylose isomerases. Each monomer is composed of two domains. Domain I (residues 1 to 321) folds into the (beta/alpha)8-barrel. Domain II (residues 322 to 387), lacking beta-strands, makes extensive contacts with domain I of an adjacent subunit. Each monomer of TcaXI contains ten beta-strands, 15 alpha-helices, and six 310-helices, while that of TthXI contains ten beta-strands, 16 alpha-helices, and five 310-helices. Although the electron density does not indicate the presence of bound metal ions in the present models of both TcaXI and TthXI, the active site residues show the conserved structural features. In order to understand the structural basis for thermostability of these enzymes, their structures have been compared with less thermostable XIs from Arthrobacter B3728 and Actinoplanes missouriensis (AXI and AmiXI), with the optimum reaction temperatures of 80 degrees C and 75 degrees C, respectively. Analyses of various factors that may affect protein thermostability indicate that the possible structural determinants of the enhanced thermostability of TcaXI/TthXI over AXI/AmiXI are (i) an increase in ion pairs and ion-pair networks, (ii) a decrease in the large inter-subunit cavities, (iii) a removal of potential deamidation/isoaspartate formation sites, and (iv) a shortened loop.

Crystal structures of thermostable xylose isomerases from Thermus caldophilus and Thermus thermophilus: possible structural determinants of thermostability.,Chang C, Park BC, Lee DS, Suh SW J Mol Biol. 1999 May 14;288(4):623-34. PMID:10329168<ref>PMID:10329168</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 1bxc" style="background-color:#fffaf0;"></div>

==See Also==
*[[D-xylose isomerase 3D structures|D-xylose isomerase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Thermus caldophilus]]
[[Category: Chang C]]
[[Category: Lee D-S]]
[[Category: Park BC]]
[[Category: Suh SW]]