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Your query returned 6 entries. Printable version
EC | 1.2.1.92 | ||||||||||||
Accepted name: | 3,6-anhydro-α-L-galactose dehydrogenase | ||||||||||||
Reaction: | 3,6-anhydro-α-L-galactopyranose + NAD(P)+ + H2O = 3,6-anhydro-L-galactonate + NAD(P)H + H+ | ||||||||||||
Systematic name: | 3,6-anhydro-α-L-galactopyranose:NAD(P)+ 1-oxidoredutase | ||||||||||||
Comments: | The enzyme, characterized from the marine bacterium Vibrio sp. EJY3, is involved in a degradation pathway for 3,6-anhydro-α-L-galactose, a major component of the polysaccharides produced by red macroalgae, such as agarose and porphyran. | ||||||||||||
Links to other databases: | BRENDA, EXPASY, KEGG, MetaCyc | ||||||||||||
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EC | 2.5.1.5 | ||||||||||||
Accepted name: | galactose-6-sulfurylase | ||||||||||||
Reaction: | Eliminates sulfate from the D-galactose 6-sulfate residues of porphyran, producing 3,6-anhydrogalactose residues | ||||||||||||
Glossary: | porphyran = is a linear polysaccharide produced by the red algae Porphyra. Its backbone is composed of about 30% agarose repeating units (alternating D-galactose and 3,6-anhydro-α-L-galactopyranose residues joined by α-(1→3)- and β-(1→4)-linkages), with the remaining residues being 3-linked β-D-galactopyranose and 4-linked α-L-galactopyranose-6-sulfate. | ||||||||||||
Other name(s): | porphyran sulfatase; galactose-6-sulfatase; galactose 6-sulfatase | ||||||||||||
Systematic name: | D-galactose-6-sulfate:alkyltransferase (cyclizing) | ||||||||||||
Links to other databases: | BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 9030-36-8 | ||||||||||||
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EC | 3.2.1.81 | ||||||||||||
Accepted name: | β-agarase | ||||||||||||
Reaction: | Hydrolysis of (1→4)-β-D-galactosidic linkages in agarose, giving the tetramer as the predominant product | ||||||||||||
Glossary: | agarose = a linear polysaccharide produced by some members of the Rhodophyta (red algae) made up from alternating D-galactose and 3,6-anhydro-α-L-galactopyranose residues joined by α-(1→3)- and β-(1→4)-linkages. In the field of oligosaccharides derived from agarose, carrageenans, etc., in which alternate residues are 3,6-anhydro sugars, the prefix ’neo’ designates an oligosaccharide whose non-reducing end is the anhydro sugar, and the absence of this prefix means that it is not. For example: neoagarobiose = 3,6-anhydro-α-L-galactopyranosyl-(1→3)-D-galactose agarobiose = β-D-galactopyranosyl-(1→4)-3,6-anhydro-L-galactose |
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Other name(s): | agarase (ambiguous); AgaA; AgaB; endo-β-agarase; agarose 3-glycanohydrolase (incorrect) | ||||||||||||
Systematic name: | agarose 4-glycanohydrolase | ||||||||||||
Comments: | Also acts on porphyran, but more slowly [1]. This enzyme cleaves the β-(1→4) linkages of agarose in a random manner with retention of the anomeric-bond configuration, producing β-anomers that give rise progressively to α-anomers when mutarotation takes place [6]. The end products of hydrolysis are neoagarotetraose and neoagarohexaose in the case of AgaA from the marine bacterium Zobellia galactanivorans, and neoagarotetraose and neoagarobiose in the case of AgaB [6]. | ||||||||||||
Links to other databases: | BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 37288-57-6 | ||||||||||||
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EC | 3.2.1.158 | ||||||||||||
Accepted name: | α-agarase | ||||||||||||
Reaction: | Endohydrolysis of (1→3)-α-L-galactosidic linkages in agarose, yielding agarotetraose as the major product | ||||||||||||
Glossary: | agarose = a linear polysaccharide produced by some members of the Rhodophyta (red algae) made up from alternating D-galactose and 3,6-anhydro-α-L-galactopyranose residues joined by α-(1→3)- and β-(1→4)-linkages. In the field of oligosaccharides derived from agarose, carrageenans, etc., in which alternate residues are 3,6-anhydro sugars, the prefix ’neo’ designates an oligosaccharide whose non-reducing end is the anhydro sugar, and the absence of this prefix means that it is not. For example: neoagarobiose = 3,6-anhydro-α-L-galactopyranosyl-(1→3)-D-galactose agarobiose = β-D-galactopyranosyl-(1→4)-3,6-anhydro-L-galactose |
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Other name(s): | agarase (ambiguous); agaraseA33 | ||||||||||||
Systematic name: | agarose 3-glycanohydrolase | ||||||||||||
Comments: | Requires Ca2+. The enzyme from Thalassomonas sp. can use agarose, agarohexaose and neoagarohexaose as substrate. The products of agarohexaose hydrolysis are dimers and tetramers, with agarotetraose being the predominant product, whereas hydrolysis of neoagarohexaose gives rise to two types of trimer. While the enzyme can also hydrolyse the highly sulfated agarose porphyran very efficiently, it cannot hydrolyse the related compounds κ-carrageenan (see EC 3.2.1.83) and ι-carrageenan (see EC 3.2.1.157) [2]. See also EC 3.2.1.81, β-agarase. | ||||||||||||
Links to other databases: | BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 63952-00-1 | ||||||||||||
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EC | 3.2.1.162 | ||||||||||||
Accepted name: | λ-carrageenase | ||||||||||||
Reaction: | Endohydrolysis of (1→4)-β-linkages in the backbone of λ-carrageenan, resulting in the tetrasaccharide α-D-Galp2,6S2-(1→3)-β-D-Galp2S-(1→4)-α-D-Galp2,6S2-(1→3)-D-Galp2S | ||||||||||||
For diagram of reaction, click here | |||||||||||||
Glossary: | For diagram of the structures of carrageenans, click here | ||||||||||||
Other name(s): | endo-β-1,4-carrageenose 2,6,2′-trisulfate-hydrolase | ||||||||||||
Systematic name: | endo-(1→4)-β-carrageenose 2,6,2′-trisulfate-hydrolase | ||||||||||||
Comments: | The enzyme from Pseudoalteromonas sp. is specific for λ-carrageenan. ι-Carrageenan (see EC 3.2.1.157, ι-carrageenase), κ-carrageenan (see EC 3.2.1.83, κ-carrageenase), agarose and porphyran are not substrates. | ||||||||||||
Links to other databases: | BRENDA, EXPASY, KEGG, MetaCyc | ||||||||||||
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EC | 3.2.1.178 | ||||||||||||
Accepted name: | β-porphyranase | ||||||||||||
Reaction: | Hydrolysis of β-D-galactopyranose-(1→4)-α-L-galactopyranose-6-sulfate linkages in porphyran | ||||||||||||
Other name(s): | porphyranase; PorA; PorB; endo-β-porphyranase | ||||||||||||
Systematic name: | porphyran β-D-galactopyranose-(1→4)-α-L-galactopyranose-6-sulfate 4-glycanohydrolase | ||||||||||||
Comments: | The backbone of porphyran consists largely (~70%) of (1→3)-linked β-D-galactopyranose followed by (1→4)-linked α-L-galactopyranose-6-sulfate [the other 30% are mostly agarobiose repeating units of (1→3)-linked β-D-galactopyranose followed by (1→4)-linked 3,6-anhydro-α-L-galactopyranose] [2]. This enzyme cleaves the (1→4) linkages between β-D-galactopyranose and α-L-galactopyranose-6-sulfate, forming mostly the disaccharide α-L-galactopyranose-6-sulfate-(1→3)-β-D-galactose, although some longer oligosaccharides of even number of residues are also observed. Since the enzyme is inactive on the non-sulfated agarose portion of the porphyran backbone, some agarose fragments are also included in the products [1]. Methylation of the D-galactose prevents the enzyme from Zobellia galactanivorans, but not that from Wenyingzhuangia fucanilytica, from binding at subsite -1 [2,3]. | ||||||||||||
Links to other databases: | BRENDA, EXPASY, KEGG, MetaCyc, PDB | ||||||||||||
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