1h80
From Proteopedia
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1,3-ALPHA-1,4-BETA-D-GALACTOSE-4-SULFATE-3,6-ANHYDRO-D-GALACTOSE-2-SULFATE 4 GALACTOHYDROLASE
Overview
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-->3) and beta(1-->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.
About this Structure
1H80 is a Single protein structure of sequence from Alteromonas sp. atcc 43554 with , , and as ligands. Active as Iota-carrageenase, with EC number 3.2.1.157 Known structural/functional Site: . Full crystallographic information is available from OCA.
Reference
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
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