EC |
2.4.1.33 |
Accepted name: |
mannuronan synthase |
Reaction: |
GDP-α-D-mannuronate + [(1→4)-β-D-mannuronosyl]n = GDP + [(1→4)-β-D-mannuronosyl]n+1 |
Glossary: |
poly[β-(1,4)-D-mannuronate] = mannuronan |
Other name(s): |
mannuronosyl transferase; alginate synthase (incorrect); alg8 (gene name); alg44 (gene name); GDP-D-mannuronate:alginate D-mannuronyltransferase |
Systematic name: |
GDP-α-D-mannuronate:mannuronan D-mannuronatetransferase |
Comments: |
The enzyme catalyses the polymerization of β-D-mannuronate residues into a mannuronan polymer, an intermediate in the biosynthesis of alginate. It is found in brown algae and in alginate-producing bacterial species from the Pseudomonas and Azotobacter genera. |
Links to other databases: |
BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 37257-31-1 |
References: |
1. |
Lin, T.-Y. and Hassid, W.Z. Pathway of alginic acid synthesis in the marine brown alga, Fucus gardneri Silva. J. Biol. Chem. 241 (1966) 5284–5297. [PMID: 5954796] |
2. |
Remminghorst, U. and Rehm, B.H. In vitro alginate polymerization and the functional role of Alg8 in alginate production by Pseudomonas aeruginosa. Appl. Environ. Microbiol. 72 (2006) 298–305. [DOI] [PMID: 16391057] |
3. |
Oglesby, L.L., Jain, S. and Ohman, D.E. Membrane topology and roles of Pseudomonas aeruginosa Alg8 and Alg44 in alginate polymerization. Microbiology 154 (2008) 1605–1615. [DOI] [PMID: 18524915] |
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[EC 2.4.1.33 created 1972, modified 2015] |
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EC |
5.1.3.37 |
Accepted name: |
mannuronan 5-epimerase |
Reaction: |
[mannuronan]-β-D-mannuronate = [alginate]-α-L-guluronate |
Glossary: |
mannuronan = a linear polymer of β-D-mannuronate residues linked by (1-4) linkages
alginate = a linear polymer of β-D-mannuronate residues linked by (1-4) linkages, with variable amounts of its C-5 epimer α-L-guluronate. |
Other name(s): |
algG (gene name); alginate epimerase; C5-mannuronan epimerase; mannuronan C-5-epimerase |
Systematic name: |
[mannuronan]-β-D-mannuronate 5-epimerase |
Comments: |
The enzyme epimerizes the C-5 bond in some β-D-mannuronate residues in mannuronan, converting them to α-L-guluronate residues, and thus modifying the mannuronan into alginate. It is found in brown algae and alginate-producing bacterial species from the Pseudomonas and Azotobacter genera. |
Links to other databases: |
BRENDA, EXPASY, KEGG, MetaCyc, PDB |
References: |
1. |
Franklin, M.J., Chitnis, C.E., Gacesa, P., Sonesson, A., White, D.C. and Ohman, D.E. Pseudomonas aeruginosa AlgG is a polymer level alginate C5-mannuronan epimerase. J. Bacteriol. 176 (1994) 1821–1830. [DOI] [PMID: 8144447] |
2. |
Morea, A., Mathee, K., Franklin, M.J., Giacomini, A., O'Regan, M. and Ohman, D.E. Characterization of algG encoding C5-epimerase in the alginate biosynthetic gene cluster of Pseudomonas fluorescens. Gene 278 (2001) 107–114. [DOI] [PMID: 11707327] |
3. |
Nyvall, P., Corre, E., Boisset, C., Barbeyron, T., Rousvoal, S., Scornet, D., Kloareg, B. and Boyen, C. Characterization of mannuronan C-5-epimerase genes from the brown alga Laminaria digitata. Plant Physiol. 133 (2003) 726–735. [DOI] [PMID: 14526115] |
4. |
Jain, S., Franklin, M.J., Ertesvag, H., Valla, S. and Ohman, D.E. The dual roles of AlgG in C-5-epimerization and secretion of alginate polymers in Pseudomonas aeruginosa. Mol. Microbiol. 47 (2003) 1123–1133. [DOI] [PMID: 12581364] |
5. |
Douthit, S.A., Dlakic, M., Ohman, D.E. and Franklin, M.J. Epimerase active domain of Pseudomonas aeruginosa AlgG, a protein that contains a right-handed β-helix. J. Bacteriol. 187 (2005) 4573–4583. [DOI] [PMID: 15968068] |
6. |
Wolfram, F., Kitova, E.N., Robinson, H., Walvoort, M.T., Codee, J.D., Klassen, J.S. and Howell, P.L. Catalytic mechanism and mode of action of the periplasmic alginate epimerase AlgG. J. Biol. Chem. 289 (2014) 6006–6019. [DOI] [PMID: 24398681] |
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[EC 5.1.3.37 created 2015] |
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