1chk

<StructureSection load='1chk' size='340' side='right' caption='[[1chk]], [[Resolution|resolution]] 2.40&Aring;' scene=''>

<table><tr><td colspan='2'>[[1chk]] is a 2 chain structure with sequence from [http://en.wikipedia.org/wiki/Strsn Strsn]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1CHK OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1CHK FirstGlance]. <br>

</td></tr><tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">CSN ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=69019 STRSN])</td></tr>

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

[[http://www.uniprot.org/uniprot/CHIS_STRSN CHIS_STRSN]] Aids in the defense against invading fungal pathogens by degrading their cell wall chitosan.

<scriptWhenChecked>select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/ch/1chk_consurf.spt"</scriptWhenChecked>

</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/chain_selection.php?pdb_ID=2ata ConSurf].

<div style="background-color:#fffaf0;">

== Publication Abstract from PubMed ==

We report the 2.4 A X-ray crystal structure of a protein with chitosan endo-hydrolase activity isolated from Streptomyces N174. The structure was solved using phases acquired by SIRAS from a two-site methyl mercury derivative combined with solvent flattening and non-crystallographic two-fold symmetry averaging, and refined to an R-factor of 18.5%. The mostly alpha-helical fold reveals a structural core shared with several classes of lysozyme and barley endochitinase, in spite of a lack of shared sequence. Based on this structural similarity we postulate a putative active site, mechanism of action and mode of substrate recognition. It appears that Glu 22 acts as an acid and Asp 40 serves as a general base to activate a water molecule for an SN2 attack on the glycosidic bond. A series of amino-acid side chains and backbone carbonyl groups may bind the polycationic chitosan substrate in a deep electronegative binding cleft.

X-ray structure of an anti-fungal chitosanase from streptomyces N174.,Marcotte EM, Monzingo AF, Ernst SR, Brzezinski R, Robertus JD Nat Struct Biol. 1996 Feb;3(2):155-62. PMID:8564542<ref>PMID:8564542</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>

</div>

<div class="pdbe-citations 1chk" style="background-color:#fffaf0;"></div>

== References ==

<references/>

[[Category: Strsn]]

[[Category: Marcotte, E M]]

[[Category: Robertus, J D]]

[[Category: Anti-fungal protein]]

[[Category: O-glycosyl]]