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Difference between revisions of "Glycoside Hydrolase Family 46"
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Glycoside hydrolases of family 46 are essentially ''endo''-beta-1,4-chitosanases (EC 3.2.1.132)that hydrolyze various links in chitosan, a polymer of beta-1,4-linked D-glucosamine (GlcN) units with a variable content (mostly 0 - 35%) of N-acetyl-D-glucosamine (GlcNAc)<cite>1</cite>, <cite>2</cite>. Among the four types of links occurring between these two kinds of subunits, all the enzymes examined for their cleavage specificity recognized productively the GlcN-GlcN links. Furthermore, the chitosanase from ''Bacillus circulans'' MH-KI recognizes also GlcN-GlcNAc links, while the chitosanase from ''Streptomyces'' sp. N174 recognizes the GlcNAc-GlcN links. | Glycoside hydrolases of family 46 are essentially ''endo''-beta-1,4-chitosanases (EC 3.2.1.132)that hydrolyze various links in chitosan, a polymer of beta-1,4-linked D-glucosamine (GlcN) units with a variable content (mostly 0 - 35%) of N-acetyl-D-glucosamine (GlcNAc)<cite>1</cite>, <cite>2</cite>. Among the four types of links occurring between these two kinds of subunits, all the enzymes examined for their cleavage specificity recognized productively the GlcN-GlcN links. Furthermore, the chitosanase from ''Bacillus circulans'' MH-KI recognizes also GlcN-GlcNAc links, while the chitosanase from ''Streptomyces'' sp. N174 recognizes the GlcNAc-GlcN links. | ||
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Revision as of 11:53, 4 February 2010
This page is currently under construction. This means that the Responsible Curator has deemed that the page's content is not quite up to CAZypedia's standards for full public consumption. All information should be considered to be under revision and may be subject to major changes.
- Author: ^^^Ryszard Brzezinski^^^
- Responsible Curator: ^^^Ryszard Brzezinski^^^
Glycoside Hydrolase Family GHnn | |
Clan | GH-I |
Mechanism | inverting |
Active site residues | known |
CAZy DB link | |
http://www.cazy.org/fam/GH46.html |
Substrate specificities
Glycoside hydrolases of family 46 are essentially endo-beta-1,4-chitosanases (EC 3.2.1.132)that hydrolyze various links in chitosan, a polymer of beta-1,4-linked D-glucosamine (GlcN) units with a variable content (mostly 0 - 35%) of N-acetyl-D-glucosamine (GlcNAc)[1], [2]. Among the four types of links occurring between these two kinds of subunits, all the enzymes examined for their cleavage specificity recognized productively the GlcN-GlcN links. Furthermore, the chitosanase from Bacillus circulans MH-KI recognizes also GlcN-GlcNAc links, while the chitosanase from Streptomyces sp. N174 recognizes the GlcNAc-GlcN links.
Kinetics and Mechanism
Content is to be added here.
Catalytic Residues
Content is to be added here.
Three-dimensional structures
Content is to be added here.
Family Firsts
- First sterochemistry determination
- Cite some reference here, with a short (1-2 sentence) explanation [3].
- First catalytic nucleophile identification
- Cite some reference here, with a short (1-2 sentence) explanation [4].
- First general acid/base residue identification
- Cite some reference here, with a short (1-2 sentence) explanation [5].
- First 3-D structure
- Cite some reference here, with a short (1-2 sentence) explanation [6].
References
- Comfort DA, Bobrov KS, Ivanen DR, Shabalin KA, Harris JM, Kulminskaya AA, Brumer H, and Kelly RM. (2007). Biochemical analysis of Thermotoga maritima GH36 alpha-galactosidase (TmGalA) confirms the mechanistic commonality of clan GH-D glycoside hydrolases. Biochemistry. 2007;46(11):3319-30. DOI:10.1021/bi061521n |
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Sinnott, M.L. (1990) Catalytic mechanisms of enzymic glycosyl transfer. Chem. Rev. 90, 1171-1202. DOI: 10.1021/cr00105a006
- He S and Withers SG. (1997). Assignment of sweet almond beta-glucosidase as a family 1 glycosidase and identification of its active site nucleophile. J Biol Chem. 1997;272(40):24864-7. DOI:10.1074/jbc.272.40.24864 |
- Robert V. Stick and Spencer J. Williams. (2009) Carbohydrates. Elsevier Science.