1h80

<table><tr><td colspan='2'>[[1h80]] is a 2 chain structure with sequence from [http://en.wikipedia.org/wiki/Altfo Altfo]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1H80 OCA]. For a <b>guided tour on the structure components</b> use [http://proteopedia.org/fgij/fg.htm?mol=1H80 FirstGlance]. <br>

</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CA:CALCIUM+ION'>CA</scene>, <scene name='pdbligand=CL:CHLORIDE+ION'>CL</scene>, <scene name='pdbligand=GOL:GLYCEROL'>GOL</scene>, <scene name='pdbligand=NA:SODIUM+ION'>NA</scene></td></tr>

<tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[1ktw|1ktw]]</td></tr>

<tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">CGIA ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=116059 ALTFO])</td></tr>

<tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/Iota-carrageenase Iota-carrageenase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.2.1.157 3.2.1.157] </span></td></tr>

<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://proteopedia.org/fgij/fg.htm?mol=1h80 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1h80 OCA], [http://pdbe.org/1h80 PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=1h80 RCSB], [http://www.ebi.ac.uk/pdbsum/1h80 PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=1h80 ProSAT]</span></td></tr>

[[http://www.uniprot.org/uniprot/CGIA_ALTFO CGIA_ALTFO]] Hydrolyzes iota-carrageenans, sulfated 1,3-alpha-1,4-beta galactans from red algal cell walls, with an inversion of anomeric configuration. Also active against hybrid iota-/nu-carrageenan, not active against kappa- or lambda-carrageenans.<ref>PMID:10934194</ref> <ref>PMID:20227066</ref> [UniProtKB:Q9F284]

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== Publication Abstract from PubMed ==

Carrageenans are gel-forming hydrocolloids extracted from the cell walls of marine red algae. They consist of d-galactose residues bound by alternate alpha(1--&gt;3) and beta(1--&gt;4) linkages and substituted by one (kappa-carrageenan), two (iota-carrageenan), or three (lambda-carrageenan) sulfate-ester groups per disaccharide repeating unit. Both the kappa- and iota-carrageenan chains adopt ordered conformations leading to the formation of highly ordered aggregates of double-stranded helices. Several kappa-carrageenases and iota-carrageenases have been cloned from marine bacteria. Kappa-carrageenases belong to family 16 of the glycoside hydrolases, which essentially encompasses polysaccharidases specialized in the hydrolysis of the neutral polysaccharides such as agarose, laminarin, lichenan, and xyloglucan. In contrast, iota-carrageenases constitute a novel glycoside hydrolase structural family. We report here the crystal structure of Alteromonas fortis iota-carrageenase at 1.6 A resolution. The enzyme folds into a right-handed parallel beta-helix of 10 complete turns with two additional C-terminal domains. Glu(245), Asp(247), or Glu(310), in the cleft of the enzyme, are proposed as candidate catalytic residues. The protein contains one sodium and one chloride binding site and three calcium binding sites shown to be involved in stabilizing the enzyme structure.

The iota-carrageenase of Alteromonas fortis. A beta-helix fold-containing enzyme for the degradation of a highly polyanionic polysaccharide.,Michel G, Chantalat L, Fanchon E, Henrissat B, Kloareg B, Dideberg O J Biol Chem. 2001 Oct 26;276(43):40202-9. Epub 2001 Aug 7. PMID:11493601<ref>PMID:11493601</ref>

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

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<div class="pdbe-citations 1h80" style="background-color:#fffaf0;"></div>

[[Category: Altfo]]

[[Category: Iota-carrageenase]]

[[Category: Chantalat, L]]

[[Category: Dideberg, O]]

[[Category: Michel, G]]

[[Category: Iota-carrageenan double helix degradation]]