IUBMB Enzyme Nomenclature


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

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


1. Duckworth, M. and Turvey, J.R. The action of a bacterial agarase on agarose, porphyran and alkali-treated porphyran. Biochem. J. 113 (1969) 687-692. [PMID: 5386190]

2. Allouch, J., Jam, M., Helbert, W., Barbeyron, T., Kloareg, B., Henrissat, B. and Czjzek, M. The three-dimensional structures of two β-agarases. J. Biol. Chem. 278 (2003) 47171-47180. [PMID: 12970344]

3. Ohta, Y., Nogi, Y., Miyazaki, M., Li, Z., Hatada, Y., Ito, S. and Horikoshi, K. Enzymatic properties and nucleotide and amino acid sequences of a thermostable β-agarase from the novel marine isolate, JAMB-A94. Biosci. Biotechnol. Biochem. 68 (2004) 1073-1081. [PMID: 15170112]

4. Ohta, Y., Hatada, Y., Nogi, Y., Miyazaki, M., Li, Z., Akita, M., Hidaka, Y., Goda, S., Ito, S. and Horikoshi, K. Enzymatic properties and nucleotide and amino acid sequences of a thermostable β-agarase from a novel species of deep-sea Microbulbifer. Appl. Microbiol. Biotechnol. 64 (2004) 505-514. [PMID: 15088129]

5. Sugano, Y., Terada, I., Arita, M., Noma, M. and Matsumoto, T. Purification and characterization of a new agarase from a marine bacterium, Vibrio sp. strain JT0107. Appl. Environ. Microbiol. 59 (1993) 1549-1554. [PMID: 8517750]

6. Jam, M., Flament, D., Allouch, J., Potin, P., Thion, L., Kloareg, B., Czjzek, M., Helbert, W., Michel, G. and Barbeyron, T. The endo-β-agarases AgaA and AgaB from the marine bacterium Zobellia galactanivorans: two paralogue enzymes with different molecular organizations and catalytic behaviours. Biochem. J. 385 (2005) 703-713. [PMID: 15456406]

[EC created 1972, modified 2006]

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