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Difference between revisions of "Glycoside Hydrolase Family 192"
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== Catalytic Residues == | == Catalytic Residues == | ||
E221(EeSGL1) is the putative general acid as this residue is structurally well-superimposed with the general acid (E262) in [[GH162]] β-1,2-glucanase from <i>Talaromyces funiculosus</i> <cite>#Tanaka2019</cite>. E221Q mutant shows drastic decrease in catalytic activity compared to the wild-type enzyme <cite>Nakajima2025</cite>. E221 is also conserved across other GH-S clan families including [[GH144]], [[GH193]], and [[GH194]]. <br> | E221(EeSGL1) is the putative general acid as this residue is structurally well-superimposed with the general acid (E262) in [[GH162]] β-1,2-glucanase from <i>Talaromyces funiculosus</i> <cite>#Tanaka2019</cite>. E221Q mutant shows drastic decrease in catalytic activity compared to the wild-type enzyme <cite>Nakajima2025</cite>. E221 is also conserved across other GH-S clan families including [[GH144]], [[GH193]], and [[GH194]]. <br> | ||
| − | Similarly, D149 (EeSGL1) is a spatially conserved residue shared with several β-1,2-glucanases; [[GH144]] (from <i>Chitinophaga pinensis</i> and <i>Xanthomonas campestris pv. campestris</i>) [[GH193]] (from <i>Sanguibacter keddieii</i>), and [[GH194]] (from <i>P. gaetbulicala</i>) <cite>#Nakajima2025, #Abe2017</cite>. D149N mutant also shows drastically decreased activity against the wild-type enzyme. Although the D149N mutation significantly diminished enzymatic activity, a | + | Similarly, D149(EeSGL1) is a spatially conserved residue shared with several β-1,2-glucanases; [[GH144]] (from <i>Chitinophaga pinensis</i> and <i>Xanthomonas campestris</i> pv. <i>campestris</i>) [[GH193]] (from <i>Sanguibacter keddieii</i>), and [[GH194]] (from <i>P. gaetbulicala</i>) <cite>#Nakajima2025, #Abe2017</cite>. D149N mutant also shows drastically decreased activity against the wild-type enzyme. Although the D149N mutation significantly diminished enzymatic activity, no complex structure with a substrate is available. |
== Three-dimensional structures == | == Three-dimensional structures == | ||
Revision as of 09:29, 25 February 2026
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| Glycoside Hydrolase Family GH192 | |
| Clan | GH-S |
| Mechanism | inverting |
| Active site residues | not known |
| CAZy DB link | |
| https://www.cazy.org/GH192.html | |
Substrate specificities
PgSGL1(H744_1c0224, KEGG) and PgSGL2(H744_2c1936, KEGG) from Photobacterium gaetbulicola and EeSGL1(A0A081KBI6, Uniprot) from Endozoicomonas elysicola are characterized. The three enzymes are specific to β-1,2-glucan among polysaccharides. They hydrolyze β-1,2-glucan endolytically to produce β-1,2-glucooligosaccharides [1].
Kinetics and Mechanism
PgSGL1 follows anomer-inverting mechanism, which is determined by measuring change of optical rotation during hydrolysis of β-1,2-glucan [1].
Catalytic Residues
E221(EeSGL1) is the putative general acid as this residue is structurally well-superimposed with the general acid (E262) in GH162 β-1,2-glucanase from Talaromyces funiculosus [2]. E221Q mutant shows drastic decrease in catalytic activity compared to the wild-type enzyme [1]. E221 is also conserved across other GH-S clan families including GH144, GH193, and GH194.
Similarly, D149(EeSGL1) is a spatially conserved residue shared with several β-1,2-glucanases; GH144 (from Chitinophaga pinensis and Xanthomonas campestris pv. campestris) GH193 (from Sanguibacter keddieii), and GH194 (from P. gaetbulicala) [1, 3]. D149N mutant also shows drastically decreased activity against the wild-type enzyme. Although the D149N mutation significantly diminished enzymatic activity, no complex structure with a substrate is available.
Three-dimensional structures
A ligand-free structure of EeSGL1 is available [1].
Family Firsts
- First stereochemisty determination
- A bacterial β-1,2-glucanase from P. gaetbulicola by monitoring the change in optical rotation [1].
- First general base residue identification
- not known.
- First general acid residue identification
- not known.
- First 3-D structure
- A bacterial β-1,2-glucanase from E. elysicola using molecular replacement [1].
References
- Nakajima M, Tanaka N, Motouchi S, Kobayashi K, Shimizu H, Abe K, Hosoyamada N, Abara N, Morimoto N, Hiramoto N, Nakata R, Takashima A, Hosoki M, Suzuki S, Shikano K, Fujimaru T, Imagawa S, Kawadai Y, Wang Z, Kitano Y, Nihira T, Nakai H, and Taguchi H. (2025). New glycoside hydrolase families of β-1,2-glucanases. Protein Sci. 2025;34(6):e70147. DOI:10.1002/pro.70147 |
- Tanaka N, Nakajima M, Narukawa-Nara M, Matsunaga H, Kamisuki S, Aramasa H, Takahashi Y, Sugimoto N, Abe K, Terada T, Miyanaga A, Yamashita T, Sugawara F, Kamakura T, Komba S, Nakai H, and Taguchi H. (2019). Identification, characterization, and structural analyses of a fungal endo-β-1,2-glucanase reveal a new glycoside hydrolase family. J Biol Chem. 2019;294(19):7942-7965. DOI:10.1074/jbc.RA118.007087 |
- Abe K, Nakajima M, Yamashita T, Matsunaga H, Kamisuki S, Nihira T, Takahashi Y, Sugimoto N, Miyanaga A, Nakai H, Arakawa T, Fushinobu S, and Taguchi H. (2017). Biochemical and structural analyses of a bacterial endo-β-1,2-glucanase reveal a new glycoside hydrolase family. J Biol Chem. 2017;292(18):7487-7506. DOI:10.1074/jbc.M116.762724 |