1chk
From Proteopedia
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|ACTIVITY= | |ACTIVITY= | ||
|GENE= CSN ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=1931 Streptomyces sp.]) | |GENE= CSN ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=1931 Streptomyces sp.]) | ||
| + | |DOMAIN= | ||
| + | |RELATEDENTRY= | ||
| + | |RESOURCES=<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://www.ebi.ac.uk/pdbsum/1chk PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=1chk RCSB]</span> | ||
}} | }} | ||
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[[Category: o-glycosyl]] | [[Category: o-glycosyl]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Mar 30 19:21:46 2008'' |
Revision as of 16:21, 30 March 2008
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| , resolution 2.40Å | |||||||
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| Sites: | |||||||
| Gene: | CSN (Streptomyces sp.) | ||||||
| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
STREPTOMYCES N174 CHITOSANASE PH5.5 298K
Overview
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.
About this Structure
1CHK is a Single protein structure of sequence from Streptomyces sp.. Full crystallographic information is available from OCA.
Reference
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
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