<text>to colour the structure by Evolutionary Conservation</text>
<text>to colour the structure by Evolutionary Conservation</text>
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</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].
</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=1ktw ConSurf].
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Revision as of 10:20, 7 February 2016
IOTA-CARRAGEENASE COMPLEXED TO IOTA-CARRAGEENAN FRAGMENTS
1ktw is a 2 chain structure with sequence from Altfo. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
iota-Carrageenans are sulfated 1,3-alpha-1,4-beta-galactans from the cell walls of red algae, which auto-associate into crystalline fibers made of aggregates of double-stranded helices. iota-Carrageenases, which constitute family 82 of glycoside hydrolases, fold into a right-handed beta-helix. Here, the structure of Alteromonas fortis iota-carrageenase bound to iota-carrageenan fragments was solved at 2.0A resolution (PDB 1KTW). The enzyme holds a iota-carrageenan tetrasaccharide (subsites +1 to +4) and a disaccharide (subsites -3, -4), thus providing the first direct determination of a 3D structure of iota-carrageenan. Electrostatic interactions between basic protein residues and the sulfate substituents of the polysaccharide chain dominate iota-carrageenan recognition. Glu245 and Asp247 are the proton donor and the base catalyst, respectively. C-terminal domain A, which was highly flexible in the native enzyme structure, adopts a alpha/beta-fold, also found in DNA/RNA-binding domains. In the substrate-enzyme complex, this polyanion-binding module shifts toward the beta-helix groove, forming a tunnel. Thus, from an open conformation which allows for the initial endo-attack of iota-carrageenan chains, the enzyme switches to a closed-tunnel form, consistent with its highly processive character, as seen from the electron-microscopy analysis of the degradation of iota-carrageenan fibers.
The structural bases of the processive degradation of iota-carrageenan, a main cell wall polysaccharide of red algae.,Michel G, Helbert W, Kahn R, Dideberg O, Kloareg B J Mol Biol. 2003 Nov 28;334(3):421-33. PMID:14623184[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
↑Michel G, Helbert W, Kahn R, Dideberg O, Kloareg B. The structural bases of the processive degradation of iota-carrageenan, a main cell wall polysaccharide of red algae. J Mol Biol. 2003 Nov 28;334(3):421-33. PMID:14623184
