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Syn/anti lateral protonation
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- Author: ^^^Wim Nerinckx^^^
- Responsible Curator: ^^^Spencer Williams^^^
Overview
This page will provide a table (and eventually a full lexicon article) on the spatial positioning of the catalytic general acid residue in the active sites of glycoside hydrolases. The table below updates those found in the seminal paper on this concept by Heightman and Vasella [1], and the more recent summary by Nerinckx et al. [2].
Table
This table can be re-sorted by clicking on the icons in the header (javascript must be turned on in your browser). To reset the page to be sorted by GH family, click the page tab above the page title.
| Family | Clan | Structure fold | Anomeric specificity | Mechanism | Syn/anti protonator | Example PDB ID | Enzyme | Organism | Ligand | General acid | Nucleophile or General base | Reference |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| GH1 | A | (β/α)8 | beta | retaining | anti | 2cer | β-glycosidase S | Sulfolobus solfataricus P2 | phenethyl glucoimidazol | Glu206 | Glu387 | [3] |
| GH2 | A | (β/α)8 | beta | retaining | anti | 2vzu | exo-β-glucosaminidase | Amicolatopsis orientalis | PNP-β-d-glucosamine | Glu469 | Glu541 | [4] |
| GH3 | none | (β/α)8 | beta | retaining | anti | 1iex | exo-1,3-1,4-glucanase | Hordeum vulgare | thiocellobiose | Glu491 | Asp285 | [5] |
| GH5 | A | (β/α)8 | beta | retaining | anti | 1h2j | endo-β-1,4-glucanase | Bacillus agaradhaerens | 2,4-DNP-2-F-cellobioside | Glu129 | Glu228 | [6] |
| GH6 | none | (β/α)8 | beta | inverting | syn | 1qjw | cellobiohydrolase 2 | Hypocrea jecorina | (Glc)2-S-(Glc)2 | Asp221 | debated | [7] |
| GH7 | B | β-jelly roll | beta | retaining | syn | 1ovw | endo-1,4-glucanase | Fusarium oxysporum | thio-Glc5 | Glu202 | Glu197 | [8] |
| GH8 | M | (α/α)6 | beta | inverting | anti | 1kwf | endo-1,4-glucanase | Clostridium thermocellum | cellopentaose | Glu95 | Asp278 | [9] |
| GH9 | none | (α/α)6 | beta | inverting | syn | 3tf4, 4tf4 | endo/exo-β-1,4-glucanase | Thermomonospora fusca | product | Glu424 | Asp55, Asp58 | [10] |
| GH10 | A | (β/α)8 | beta | retaining | anti | 2xyl | xylanase B (Cex) | Cellulomonas fimi | Xyl-2-F-xylosyl | Glu127 | Glu233 | [11] |
| GH11 | C | β-jelly roll | beta | retaining | syn | 1bvv | xylanase | Bacillus circulans | Xyl-2-F-xylosyl | Glu172 | Glu78 | [12] |
| GH12 | C | β-jelly roll | beta | retaining | syn | 2nlr | endo-1,4-glucanase | Streptomyces lividans | Glc2-2-F-glucosyl | Glu203 | Glu120 | [13] |
| GH13 | H | (β/α)8 | alpha | retaining | anti | 1cxk | β-cyclodextrin glucanotransferase | Bacillus circulans | maltononaose | Glu257 | Asp229 | [14] |
| GH14 | none | (β/α)8 | alpha | inverting | syn | 1b9z | β-amylase | Bacillus cereus | product | Glu172 | Glu367 | [15] |
| GH15 | L | (α/α)6 | alpha | inverting | syn | 1gah | glucoamylase | Aspergillus awamori | acarbose | Glu179 | Glu400 | [16] |
| GH16 | B | β-jelly roll | beta | retaining | syn | 1urx | β-agarase A | Zobellia galactanivorans | product | Glu152 | Glu147 | [17] |
| GH17 | A | (β/α)8 | beta | retaining | predicted anti by clan | see e.g. at GH1 | ||||||
| GH18 | K | (β/α)8 | beta | retaining | anti | 1ffr | chitinase A | Serratia marcescens | (NAG)6 | Glu315 | internal | [18] |
| GH20 | K | (β/α)8 | beta | retaining | anti | 1c7s | chitobiase | Serratia marcescens | chitobiose | Glu540 | internal | [19] |
| GH22 | none | lysozyme type | beta | retaining | syn | 1h6m | lysozyme C | Gallus gallus | Chit-2-F-chitosyl | Glu35 | Asp52 | [20] |
| GH23 | none | lysozyme type | beta | inverting | syn | 1lsp | lysozyme G | Cygnus atratus | Bulgecin A | Glu73 | internal | [21] |
| GH24 | I | α + β | beta | inverting | syn | 148l | lysozyme E | Bacteriophage T4 | chitobiosyl | Glu11 | Glu26 | [22] |
| GH26 | A | (β/α)8 | beta | retaining | anti | 1gw1 | mannanase A | Cellvibrio japonicus | (Man2)-2-F-mannosyl | Glu212 | Glu320 | [23] |
| GH27 | D | (β/α)8 | alpha | retaining | anti | 1ktc | α-N-acetyl galactosaminidase | Gallus gallus | NAGal | Asp201 | Asp410 | [24] |
| GH29 | none | (β/α)8 | alpha | retaining | syn | 1hl9 | α-l-fucosidase | Thermotoga maritima | 2-F-fuco- pyranosyl | Glu266 | Asp224 | [25] |
| GH30 | A | (β/α)8 | beta | retaining | predicted anti by clan | see e.g. at GH1 | ||||||
| GH31 | D | (β/α)8 | alpha | retaining | anti | 1xsk | α-xylosidase | Escherechia coli | 5-F-xylosyl | Asp482 | Asp416 | [26] |
| GH32 | J | 5-fold β-propeller | alpha | retaining | anti | 2add | fructan β-(2,1)-fructosidase | Cichorium intybus | sucrose | Glu201 | Asp22 | [27] |
| GH33 | E | 6-fold β-propeller | alpha | retaining | anti | 1s0k | trans-sialidase | Trypanosoma cruzi | 2-F,3-F-sialosyl | Asp59 | Tyr342 | [28] |
| GH34 | E | 6-fold β-propeller | alpha | retaining | anti | 2bat | neuraminidase | Influenza A virus | sialic acid | Asp151 | Tyr406 | [29] |
| GH35 | A | (β/α)8 | beta | retaining | predicted anti by clan | see e.g. at GH1 | ||||||
| GH37 | G | (α/α)6 | alpha | inverting | anti | 2jf4 | trehalase | Escherechia coli | validoxylamine | Asp312 | Glu496 | [30] |
| GH38 | none | (β/α)7 | alpha | retaining | anti | 1qwn | α-mannosidase II | Drosophila melanogaster | 5-F-β-l-gulosyl | Asp341 | Asp204 | [31] |
| GH39 | A | (β/α)8 | beta | retaining | anti | 1uhv | β-xylosidase | Thermoanaerobacterium saccharolyticum | 2-F-xylosyl | Glu160 | Glu277 | [32] |
| GH42 | A | (β/α)8 | beta | retaining | anti | 1kwk | β-galactosidase | Thermus thermophylus A4 | d-galactose | Glu141 | Glu312 | [33] |
| GH44 | none | (β/α)8 | beta | retaining | anti | 2eqd | endoglucanase | Clostridium thermocellum | cellooctaose | Glu186 | Glu359 | [34] |
| GH45 | none | 6-strand. β-barrel | beta | inverting | syn | 4eng | endo-1,4-glucanase | Humicola insolens | product | Asp121 | Asp10 | [35] |
| GH46 | I | α + β | beta | inverting | predicted syn by clan | see at GH24 | ||||||
| GH47 | none | (α/α)7 | alpha | inverting | anti | 1x9d | α-mannosidase I | Homo sapiens | Michaelis | Asp463 | Glu599 | [36], [37] |
| GH48 | M | (α/α)6 | beta | inverting | predicted anti by clan | see at GH8 | ||||||
| GH50 | A | (β/α)8 | beta | retaining | predicted anti by clan | see e.g. at GH1 | ||||||
| GH51 | A | (β/α)8 | alpha | retaining | anti | 1pz2 | α-l-arabino- furanosidase | Geobacillus stearothermophilus | l-arabino- furanosyl | Glu175 | Glu294 | [38] |
| GH53 | A | (β/α)8 | beta | retaining | predicted anti by clan | see e.g. at GH1 | ||||||
| GH54 | none | β-sandwich | alpha | retaining | anti | 1wd4 | α-l-arabino- furanosidase B | Aspergillus kawachii | l-arabino- furanose | Asp297 | Glu221 | [39] |
| GH56 | none | (β/α)7 | beta | retaining | anti | 1fcv | hyaluronidase | Apis mellifera | (hyaluron.)4 | Glu113 | internal | [40] |
| GH57 | none | (β/α)7 | alpha | retaining | anti | 1kly | glucanotransferase | Thermococcus litoralis | acarbose | Asp214 | Glu123 | [41] |
| GH59 | A | (β/α)8 | beta | retaining | predicted anti by clan | see e.g. at GH1 | ||||||
| GH63 | G | (α/α)6 | alpha | inverting | predicted anti by clan | see at GH37 | ||||||
| GH65 | L | (α/α)6 | alpha | inverting | predicted syn by clan | see at GH15 | ||||||
| GH67 | none | (β/α)8 | alpha | inverting | syn | 1gql | α-glucuronidase | Cellvibrio japonicus Ueda107 | d-glucuronic acid | Glu292 | unknown | [42] |
| GH68 | J | 5-fold β-propeller | beta | retaining | anti | 1pt2 | levansucrase | Bacillus subtilis | sucrose | Glu342 | Asp86 | [43] |
| GH70 | H | (β/α)8 | alpha | retaining | predicted anti by clan | see e.g. at GH13 | ||||||
| GH72 | A | (β/α)8 | beta | retaining | predicted anti by clan | see e.g. at GH1 | ||||||
| GH74 | none | 7-fold β-propeller | beta | inverting | syn | 2ebs | cellobiohydrolase (OXG-RCBH) | Geotrichum sp. m128 | xyloglucan heptasaccharide | Asp465 | Asp35 | [44] |
| GH77 | H | (β/α)8 | alpha | retaining | anti | 1esw | amylomaltase | Thermus aquaticus | acarbose | Asp395 | Asp293 | [45] |
| GH79 | A | (β/α)8 | beta | retaining | predicted anti by clan | see e.g. at GH1 | ||||||
| GH80 | I | α + β | beta | inverting | predicted syn by clan | see at GH24 | ||||||
| GH83 | E | 6-fold β-propeller | alpha | retaining | predicted anti by clan | see e.g. at GH33 | ||||||
| GH85 | K | (β/α)8 | beta | retaining | predicted anti by clan | see e.g. at GH18 | ||||||
| GH86 | A | (β/α)8 | beta | retaining | predicted anti by clan | see e.g. at GH1 | ||||||
| GH89 | none | (β/α)8 | alpha | retaining | anti | 2vcb | α-N-acetyl- glucosaminidase | Clostridium perfringens | PUGNAc | Glu483 | Glu601 | [46] |
| GH92 | none | (α/α)6 + β-sandw. | alpha | inverting | anti | 2ww1 | α-1,2-mannosidase | Bacteroides thetaiota- omicron VPI-5482 | thiomannobioside | Glu533 | Asp644 Asp642 | [47] |
| GH93 | E | 6-fold β-propeller | alpha | retaining | predicted anti by clan | see e.g. at GH33 | ||||||
| GH94 | none | (α/α)6 | beta | inverting | syn | 1v7x | chitobiose phosphorylase | Vibrio proteolyticus | GlcNAc | Asp492 | phosphate | [48] |
| GH95 | none | (α/α)6 | alpha | inverting | anti | 2ead | α-1,2-l-fucosidase | Bifidobacterium bifidum | substrate | Glu566 | Asn423 Asp766 | [49] |
| GH102 | none | double-ψ β-barrel | beta | retaining | syn | 2pi8 | lytic transglycosylase A | Escherechia coli | chitohexaose | Asp308 | none | [50] |
| GH113 | A | (β/α)8 | beta | retaining | predicted anti by clan | see e.g. at GH1 |
References
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-
Heightman, T.D. and Vasella, A.T. (1999) Recent Insights into Inhibition, Structure, and Mechanism of Configuration-Retaining Glycosidases. Angewandte Chemie-International Edition 38(6), 750-770. Article online.
- Error fetching PMID 15642336:
- Error fetching PMID 17002288:
- Error fetching PMID 18976664:
- Hrmova M, Varghese JN, De Gori R, Smith BJ, Driguez H, and Fincher GB. (2001). Catalytic mechanisms and reaction intermediates along the hydrolytic pathway of a plant beta-D-glucan glucohydrolase. Structure. 2001;9(11):1005-16. DOI:10.1016/s0969-2126(01)00673-6 |
- Error fetching PMID 12595701:
- Rouvinen J, Bergfors T, Teeri T, Knowles JK, and Jones TA. (1990). Three-dimensional structure of cellobiohydrolase II from Trichoderma reesei. Science. 1990;249(4967):380-6. DOI:10.1126/science.2377893 |
- Error fetching PMID 8952478:
- Error fetching PMID 11884144:
- Error fetching PMID 9537366:
- Error fetching PMID 9537990:
- Error fetching PMID 10220321:
- Sulzenbacher G, Mackenzie LF, Wilson KS, Withers SG, Dupont C, and Davies GJ. (1999). The crystal structure of a 2-fluorocellotriosyl complex of the Streptomyces lividans endoglucanase CelB2 at 1.2 A resolution. Biochemistry. 1999;38(15):4826-33. DOI:10.1021/bi982648i |
- Uitdehaag JC, Mosi R, Kalk KH, van der Veen BA, Dijkhuizen L, Withers SG, and Dijkstra BW. (1999). X-ray structures along the reaction pathway of cyclodextrin glycosyltransferase elucidate catalysis in the alpha-amylase family. Nat Struct Biol. 1999;6(5):432-6. DOI:10.1038/8235 |
- Error fetching PMID 10353816:
- Error fetching PMID 8679589:
- Error fetching PMID 15062085:
- Error fetching PMID 11560481:
- Error fetching PMID 10884356:
- Vocadlo DJ, Davies GJ, Laine R, and Withers SG. (2001). Catalysis by hen egg-white lysozyme proceeds via a covalent intermediate. Nature. 2001;412(6849):835-8. DOI:10.1038/35090602 |
- Error fetching PMID 15299731:
- Error fetching PMID 8259514:
- Ducros VM, Zechel DL, Murshudov GN, Gilbert HJ, Szabó L, Stoll D, Withers SG, and Davies GJ. (2002). Substrate distortion by a beta-mannanase: snapshots of the Michaelis and covalent-intermediate complexes suggest a B(2,5) conformation for the transition state. Angew Chem Int Ed Engl. 2002;41(15):2824-7. DOI:10.1002/1521-3773(20020802)41:15<2824::AID-ANIE2824>3.0.CO;2-G |
- Error fetching PMID 12005440:
- Sulzenbacher G, Bignon C, Nishimura T, Tarling CA, Withers SG, Henrissat B, and Bourne Y. (2004). Crystal structure of Thermotoga maritima alpha-L-fucosidase. Insights into the catalytic mechanism and the molecular basis for fucosidosis. J Biol Chem. 2004;279(13):13119-28. DOI:10.1074/jbc.M313783200 |
- Error fetching PMID 15501829:
- Error fetching PMID 17335500:
- Error fetching PMID 15130470:
- Error fetching PMID 1438172:
- Gibson RP, Gloster TM, Roberts S, Warren RA, Storch de Gracia I, García A, Chiara JL, and Davies GJ. (2007). Molecular basis for trehalase inhibition revealed by the structure of trehalase in complex with potent inhibitors. Angew Chem Int Ed Engl. 2007;46(22):4115-9. DOI:10.1002/anie.200604825 |
- Error fetching PMID 12960159:
- Error fetching PMID 14659747:
- Error fetching PMID 12215416:
- Error fetching PMID 17905739:
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- Karaveg K, Siriwardena A, Tempel W, Liu ZJ, Glushka J, Wang BC, and Moremen KW. (2005). Mechanism of class 1 (glycosylhydrolase family 47) {alpha}-mannosidases involved in N-glycan processing and endoplasmic reticulum quality control. J Biol Chem. 2005;280(16):16197-207. DOI:10.1074/jbc.M500119200 |
- Cantú D, Nerinckx W, and Reilly PJ. (2008). Theory and computation show that Asp463 is the catalytic proton donor in human endoplasmic reticulum alpha-(1-->2)-mannosidase I. Carbohydr Res. 2008;343(13):2235-42. DOI:10.1016/j.carres.2008.05.026 |
- Error fetching PMID 14517232:
- Error fetching PMID 15292273:
- Error fetching PMID 11080624:
- Imamura H, Fushinobu S, Yamamoto M, Kumasaka T, Jeon BS, Wakagi T, and Matsuzawa H. (2003). Crystal structures of 4-alpha-glucanotransferase from Thermococcus litoralis and its complex with an inhibitor. J Biol Chem. 2003;278(21):19378-86. DOI:10.1074/jbc.M213134200 |
- Error fetching PMID 11937059:
- Error fetching PMID 14517548:
- Error fetching PMID 17498741:
- Przylas I, Terada Y, Fujii K, Takaha T, Saenger W, and Sträter N. (2000). X-ray structure of acarbose bound to amylomaltase from Thermus aquaticus. Implications for the synthesis of large cyclic glucans. Eur J Biochem. 2000;267(23):6903-13. DOI:10.1046/j.1432-1033.2000.01790.x |
- Error fetching PMID 18443291:
-
Zhu et al. (2010) Nature Chemical Biology in the press; DOI: 10.1038/nchembio.278 direct link.
- Error fetching PMID 15274915:
- Nagae M, Tsuchiya A, Katayama T, Yamamoto K, Wakatsuki S, and Kato R. (2007). Structural basis of the catalytic reaction mechanism of novel 1,2-alpha-L-fucosidase from Bifidobacterium bifidum. J Biol Chem. 2007;282(25):18497-18509. DOI:10.1074/jbc.M702246200 |
- Error fetching PMID 17502382: