1chk: Difference between revisions
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[[Image:1chk.gif|left|200px]] | [[Image:1chk.gif|left|200px]] | ||
'''STREPTOMYCES N174 CHITOSANASE PH5.5 298K''' | {{Structure | ||
|PDB= 1chk |SIZE=350|CAPTION= <scene name='initialview01'>1chk</scene>, resolution 2.40Å | |||
|SITE= <scene name='pdbsite=CAT:Putative+Catalytic+Residues'>CAT</scene> | |||
|LIGAND= | |||
|ACTIVITY= | |||
|GENE= CSN ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=1931 Streptomyces sp.]) | |||
}} | |||
'''STREPTOMYCES N174 CHITOSANASE PH5.5 298K''' | |||
==Overview== | ==Overview== | ||
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==About this Structure== | ==About this Structure== | ||
1CHK is a [ | 1CHK is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Streptomyces_sp. Streptomyces sp.]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1CHK OCA]. | ||
==Reference== | ==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:[http:// | 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:[http://www.ncbi.nlm.nih.gov/pubmed/8564542 8564542] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Streptomyces sp.]] | [[Category: Streptomyces sp.]] | ||
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[[Category: o-glycosyl]] | [[Category: o-glycosyl]] | ||
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Mar 20 10:24:26 2008'' | ||
Revision as of 08:24, 20 March 2008
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| 1chk, resolution 2.40Å | |||||||||||||
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| Sites: | CAT | ||||||||||||
| Gene: | CSN (Streptomyces sp.) | ||||||||||||
| 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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