1cns: Difference between revisions
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< | ==CRYSTAL STRUCTURE OF CHITINASE AT 1.91A RESOLUTION== | ||
<StructureSection load='1cns' size='340' side='right'caption='[[1cns]], [[Resolution|resolution]] 1.91Å' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[1cns]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Hordeum_vulgare Hordeum vulgare]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1CNS OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1CNS 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]] 1.91Å</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=1cns FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1cns OCA], [https://pdbe.org/1cns PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1cns RCSB], [https://www.ebi.ac.uk/pdbsum/1cns PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1cns ProSAT]</span></td></tr> | |||
</table> | |||
== Function == | |||
[https://www.uniprot.org/uniprot/CHI2_HORVU CHI2_HORVU] Defense against chitin containing fungal pathogens. | |||
== 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/cn/1cns_consurf.spt"</scriptWhenChecked> | |||
<scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview03.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=1cns ConSurf]. | |||
<div style="clear:both"></div> | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
Chitinase from barley seeds is a monomeric enzyme with 243 amino-acid residues and it plays a role as a defense protein. Its structure, previously determined at 2.8 A resolution by multiple isomorphous replacement method, is mainly alpha-helical [Hart, Monzingo, Ready, Ernst & Robertus, (1993). J. Mol. Biol. 229, 189-193]. The crystallization and preliminary X-ray data of the same enzyme in a different crystal form has been reported independently [Song, Hwang, Kim & Suh, (1993). Proteins, 17, 107-109}, the asymmetric unit of which contains two chitinase molecules. As a step toward understanding the general principles of catalysis, reported here is the structure of chitinase from barley seeds in this crystal form, as determined by molecular replacement and subsequently refined at 2.0 A resolution, with incorporation of partial data to 1.9 A (R factor of 18.9% for 31 038 unique reflections with F(o)> 2sigma(F) in the range 8.0-1.9 A). The r.m.s. deviations from ideal stereochemistry are 0.013 A for bond lengths and 1.32 degrees for bond angles. A superposition of the two independent molecules in the asymmetric unit gives an r.m.s. difference of 0.55 A for all protein atoms (0.43 and 0.74 A for main-chain and side-chain atoms, respectively). When the refined model of each chitinase molecule in the asymmetric unit is superposed with the starting model, the r.m.s. difference for all shared protein atoms is 0.99 A for molecule 1 and 0.85 A for molecule 2, respectively. Through a sequence comparison with homologous plant chitinases as well as a structural comparison with the active sites of other glycosidases, key catalytic residues have been identified and the active site has been located in the three-dimensional structure of the barley chitinase. The present structure, refined at an effective resolution of 2.0 A with incorporation of partial data to 1.9 A, represents a significant improvement in resolution compared to the previously reported model. The improved resolution has enabled the location of solvent atoms, including water molecules near the catalytic residues, in addition to the positioning of protein atoms with greater accuracy. | |||
Refined structure of the chitinase from barley seeds at 2.0 a resolution.,Song HK, Suh SW Acta Crystallogr D Biol Crystallogr. 1996 Mar 1;52(Pt 2):289-98. PMID:15299702<ref>PMID:15299702</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
<div class="pdbe-citations 1cns" style="background-color:#fffaf0;"></div> | |||
==See Also== | |||
*[[Chitinase 3D structures|Chitinase 3D structures]] | |||
== References == | |||
<references/> | |||
__TOC__ | |||
</StructureSection> | |||
== | |||
== | |||
[[Category: Hordeum vulgare]] | [[Category: Hordeum vulgare]] | ||
[[Category: | [[Category: Large Structures]] | ||
[[Category: Song | [[Category: Song HK]] | ||
[[Category: Suh | [[Category: Suh SW]] | ||
Latest revision as of 02:52, 21 November 2024
CRYSTAL STRUCTURE OF CHITINASE AT 1.91A RESOLUTIONCRYSTAL STRUCTURE OF CHITINASE AT 1.91A RESOLUTION
Structural highlights
FunctionCHI2_HORVU Defense against chitin containing fungal pathogens. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedChitinase from barley seeds is a monomeric enzyme with 243 amino-acid residues and it plays a role as a defense protein. Its structure, previously determined at 2.8 A resolution by multiple isomorphous replacement method, is mainly alpha-helical [Hart, Monzingo, Ready, Ernst & Robertus, (1993). J. Mol. Biol. 229, 189-193]. The crystallization and preliminary X-ray data of the same enzyme in a different crystal form has been reported independently [Song, Hwang, Kim & Suh, (1993). Proteins, 17, 107-109}, the asymmetric unit of which contains two chitinase molecules. As a step toward understanding the general principles of catalysis, reported here is the structure of chitinase from barley seeds in this crystal form, as determined by molecular replacement and subsequently refined at 2.0 A resolution, with incorporation of partial data to 1.9 A (R factor of 18.9% for 31 038 unique reflections with F(o)> 2sigma(F) in the range 8.0-1.9 A). The r.m.s. deviations from ideal stereochemistry are 0.013 A for bond lengths and 1.32 degrees for bond angles. A superposition of the two independent molecules in the asymmetric unit gives an r.m.s. difference of 0.55 A for all protein atoms (0.43 and 0.74 A for main-chain and side-chain atoms, respectively). When the refined model of each chitinase molecule in the asymmetric unit is superposed with the starting model, the r.m.s. difference for all shared protein atoms is 0.99 A for molecule 1 and 0.85 A for molecule 2, respectively. Through a sequence comparison with homologous plant chitinases as well as a structural comparison with the active sites of other glycosidases, key catalytic residues have been identified and the active site has been located in the three-dimensional structure of the barley chitinase. The present structure, refined at an effective resolution of 2.0 A with incorporation of partial data to 1.9 A, represents a significant improvement in resolution compared to the previously reported model. The improved resolution has enabled the location of solvent atoms, including water molecules near the catalytic residues, in addition to the positioning of protein atoms with greater accuracy. Refined structure of the chitinase from barley seeds at 2.0 a resolution.,Song HK, Suh SW Acta Crystallogr D Biol Crystallogr. 1996 Mar 1;52(Pt 2):289-98. PMID:15299702[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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