Syn/anti lateral protonation

This page has been approved by the Responsible Curator as essentially complete. CAZypedia is a living document, so further improvement of this page is still possible. If you would like to suggest an addition or correction, please contact the page's Responsible Curator directly by e-mail.

• Author: ^^^Wim Nerinckx^^^
• Responsible Curator: ^^^Spencer Williams^^^

---

Overview

This page provides a table that summarizes the spatial positioning of the catalytic general acid residue in the active sites of glycoside hydrolases, relative to the substrate. The table below updates those found in the seminal paper on this concept by Heightman and Vasella [1], and a following paper by Nerinckx et al. [2].

Background

The "not from above, but from the side" concept of semi-lateral glycosidic oxygen protonation by glycoside hydrolases was introduced by Heightman and Vasella [1]. It was originally only described for beta-equatorial glycoside hydrolases, but appears to be equally applicable to enzymes acting on an alpha-axial glycosidic bond [2]. When dividing subsite -1 into half-spaces by a plane defined by the glycosidic oxygen and C1' and H1' of the –1 glycoside, many ligand-complexed structures reveal that the proton donor is positioned either in the syn half-space (near the ring-oxygen of the –1 glycoside), or in the anti half-space (on the opposite side of the ring-oxygen). Members of the same GH family appear to share a common syn or anti protonator arrangement and further, this specificity appears to be preserved within Clans of families. This page's compilation of subsite -1 occupied complexes shows that about 70% of all GH families are anti protonators.

Closer inspection of crystal structures of –1/+1 subsite-spanning substrates, or substrate-analogue ligands, in complex with enzymes reveals a further intriguing corollary [2, 3]. In substrate-bound complexes with anti protonating GH enzymes, the scissile anomeric bond (often studied using the thio-analogue) shows a dihedral angle φ (O5'-C1'-[O,S]x-Cx) that is in the lowest-energy synclinal (gauche) conformation. The rationale for this is that a minus synclinal dihedral angle φ for an equatorial glycosidic bond, or plus synclinal for an axial glycosidic bond [4], allows for hyperconjugative overlap of the C1'-O5' antibonding orbital with an antiperiplanar-oriented lone pair orbital lobe of the glycosidic oxygen, thereby creating partial double bond character and stabilization of the glycosidic bond by 4–5 kcal/mol; this ground-state stabilizing phenomenon is known as the ‘exo-anomeric effect’ [5, 6]. Anti protonation occurs on the glycosidic oxygen’s antiperiplanar lone pair, thereby removing the stabilizing exo-anomeric effect. This suggests that anti protonation is an enzymic approach for lowering the activation barrier leading to the transition state (Figure 1 centre).

Syn protonating glycoside hydrolases apparently make use of a different approach [2, 3]. In many –1/+1 subsite-spanning ligand complexes, the dihedral angle φ of the scissile anomeric bond has been rotated away from its lowest-energy synclinal position: clockwise to minus-anticlinal or antiperiplanar for beta-equatorial; counterclockwise to plus-anticlinal or antiperiplanar for alpha-axial anomeric bonds. This removes the hyperconjugative overlap and thus also the stabilizing exo-anomeric effect. And because of this rotation, a lone pair of the glycosidic oxygen is directed into the syn half-space, allowing it to be protonated by the syn-positioned proton donor (Figure 1 right).

Figure 1. Newman projections, with the glycosidic oxygen as proximal atom and the anomeric carbon as distal atom, showing anti (centre) versus syn (right) semi-lateral protonation in beta-equatorial (top) and alpha-axial (bottom) glycoside hydrolases. The indicated φ is the dihedral angle for O5'-C1'-O4-C4.

Table of syn/anti protonation examples

This table contains only one example per GH family of a ligand-complexed protein structure where the syn or anti positioning of the proton donor can be clearly observed; other examples may be available on a family-by-family basis. The reader is thus advised to consult the CAZy database for a current, comprehensive list of CAZyme structures. Where available, the selected examples are Michaelis-type complexes with the ligand spanning the -1/+1 subsites, since these have an intact glycosidic or thioglycosidic bond, or are N-analogs of the substrate (e.g. acarbose). In some examples, the proton donor has been mutated (e.g., to the corresponding amide or to an alanine), and in those cases one may wish to look at a superposition of the given PDB example with the structure of the native enzyme. If a Michaelis-type complex is not yet available, the second and third example choices, respectively, are trapped glycosyl-enzyme intermediates and product complexes where subsite -1 is occupied.

Please also be aware that this is a large table with many data. Please contact the page Author or Responsible Curator with corrections.

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 View tab at the very top of the page.

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 glucoimidazole	Glu206	Glu387	[7]
GH2	A	(β/α)8	beta	retaining	anti	2vzu	exo-β-glucosaminidase	Amicolatopsis orientalis	PNP-β-d-glucosamine	Glu469	Glu541	[8]
GH3	none	(β/α)8	beta	retaining	anti	1iex	exo-1,3-1,4-glucanase	Hordeum vulgare	thiocellobiose	Glu491	Asp285	[9]
GH5	A	(β/α)8	beta	retaining	anti	1h2j	endo-β-1,4-glucanase	Bacillus agaradhaerens	2',4'-DNP-2-F-cellobioside	Glu129	Glu228	[10]
GH6	none	(β/α)8	beta	inverting	syn	1qjw	cellobiohydrolase 2	Hypocrea jecorina	(Glc)2-S-(Glc)2	Asp221	debated	[11]
GH7	B	β-jelly roll	beta	retaining	syn	1ovw	endo-1,4-glucanase	Fusarium oxysporum	thio-(Glc)5	Glu202	Glu197	[12]
GH8	M	(α/α)6	beta	inverting	anti	1kwf	endo-1,4-glucanase	Clostridium thermocellum	cellopentaose	Glu95	Asp278	[13]
GH9	none	(α/α)6	beta	inverting	syn	1rq5	cellobiohydrolase	Clostridium thermocellum	cellotetraose	Glu795	Asp383	[14]
GH10	A	(β/α)8	beta	retaining	anti	2d24	β-1,4-xylanase	Streptomyces olivaceoviridis E-86	xylopentaose	Glu128	Glu236	[15]
GH11	C	β-jelly roll	beta	retaining	syn	4hk8	endo-β-1,4-xylanase	Hypocrea jecorina	xylohexaose	Glu177	Glu86	[16]
GH12	C	β-jelly roll	beta	retaining	syn	1w2u	endoglucanase	Humicola grisea	thiocellotetraose	Glu205	Glu120	[17]
GH13	H	(β/α)8	alpha	retaining	anti	1cxk	β-cyclodextrin glucanotransferase	Bacillus circulans	maltononaose	Glu257	Asp229	[18]
GH14	none	(β/α)8	alpha	inverting	syn	1itc	β-amylase	Bacillus cereus	maltopentaose	Glu172	Glu367	[19]
GH15	L	(α/α)6	alpha	inverting	anti	1dog	glucoamylase	Aspergillus awamori	1-deoxynojirimycin	Glu179	Glu400	[20]
GH16	B	β-jelly roll	beta	retaining	syn	1urx	β-agarase A	Zobellia galactanivorans	oligoagarose	Glu152	Glu147	[21]
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	[22]
GH19	none	lysozyme type	beta	inverting	syn	3wh1	chitinase	Bryum coronatum	(GlcNAc)4	Glu61	Glu70	[23]
GH20	K	(β/α)8	beta	retaining	anti	1c7s	chitobiase	Serratia marcescens	chitobiose	Glu540	internal	[24]
GH22	none	lysozyme type	beta	retaining	syn	1h6m	lysozyme C	Gallus gallus	Chit-2-F-chitosyl	Glu35	Asp52	[25]
GH23	none	lysozyme type	beta	inverting	syn	1lsp	lysozyme G	Cygnus atratus	Bulgecin A	Glu73	internal	[26]
GH24	I	α + β	beta	inverting	syn	148l	lysozyme E	Bacteriophage T4	chitobiosyl	Glu11	Glu26	[27]
GH26	A	(β/α)8	beta	retaining	anti	2vx6	exo-β-mannanase	Cellvibrio japonicus Ueda107	Gal1Man4	Glu221	Glu338	[28]
GH27	D	(β/α)8	alpha	retaining	anti	3lrm	α-galactosidase	Saccharomyces cerevisiae	raffinose	Asp209	Asp141	[29]
GH28	N	β-helix	alpha	inverting	anti	2uvf	exo-polygalacturonosidase	Yersinia enterocolitica ATCC9610D	digalacturonic acid	Asp402	Asp381 Asp403	[30]
GH29	none	(β/α)8	alpha	retaining	syn	3uet	α-1,3/4-fucosidase	Bifidobacterium longum subsp. infantis	lacto-N-fucopentaose II	Glu217	Asp172	[31]
GH30	A	(β/α)8	beta	retaining	anti	2v3d	glucocerebrosidase 1	Homo sapiens	N-butyl-deoxynojirimycin	Glu235	Glu340	[32]
GH31	D	(β/α)8	alpha	retaining	anti	2qmj	maltase-glucoamylase	Homo sapiens	acarbose	Asp542	Asp443	[33]
GH32	J	5-fold β-propeller	beta	retaining	anti	2add	fructan β-(2,1)-fructosidase	Cichorium intybus	sucrose	Glu201	Asp22	[34]
GH33	E	6-fold β-propeller	alpha	retaining	anti	1s0i	transsialidase	Trypanosoma cruzi	sialyllactose	Asp59	Tyr342	[35]
GH34	E	6-fold β-propeller	alpha	retaining	anti	4gzw	N2 neuraminidase	Influenza A Tanzania/205/2010 H3N2	α-d-Neup5Ac-(2,3)-β-d-Galp-(1,4)-β-d-GlcpNAc	Asp151	Tyr406	[36]
GH35	A	(β/α)8	beta	retaining	anti	3ogv	β-galactosidase	Hypocrea jecorina	2-phenylethyl 1-thio-β-d-galactopyranoside	Glu200	Glu298	[37]
GH36	D	(β/α)8	alpha	retaining	anti	4fns	β-galactosidase	Geobacillus stearothermophilus	1-deoxy galactonojirimycin	Asp584	Asp478	[38]
GH37	G	(α/α)6	alpha	inverting	anti	2jf4	trehalase	Escherechia coli	validoxylamine	Asp312	Glu496	[39]
GH38	none	(β/α)7	alpha	retaining	anti	3czn	Golgi α-mannosidase II	Drosophila melanogaster	GlcNAcMan(5)GlcNAc(2)	Asp341	Asp204	[40]
GH39	A	(β/α)8	beta	retaining	anti	2bfg	β-xylosidase	Geobacillus stearothermophilus	2,5-dinitrophenyl-β-d-xyloside	Glu160	Glu278	[41]
GH42	A	(β/α)8	beta	retaining	anti	4ucf	β-galactosidase	Bifidobacterium bifidum	d-galactose	Glu161	Glu320	[42]
GH43	F	5-fold β-propeller	alpha	inverting	anti	3akh	exo-1,5-α-l-arabinofuranosidase	Streptomyces avermitilis	α-1,5-arabinofuranotriose	Glu196	Asp220	[43]
GH44	none	(β/α)8	beta	retaining	anti	2eqd	endoglucanase	Clostridium thermocellum	cellooctaose	Glu186	Glu359	[44]
GH45	none	6-strand. β-barrel	beta	inverting	syn	4eng	endo-1,4-glucanase	Humicola insolens	cellohexaose	Asp121	Asp10	[45]
GH46	I	lysozyme type	beta	inverting	syn	4olt	chitosanase	Microbacterium sp. OU01	hexa-glucosamine	Glu25	Asp43	[46]
GH47	none	(α/α)7	alpha	inverting	anti	1x9d	α-mannosidase I	Homo sapiens	Me-2-S-(α-Man)-2-thio-α-Man	Asp463	Glu599	[47], [48]
GH48	M	(α/α)6	beta	inverting	predicted anti by clan	see at GH8
GH49	N	β-helix	alpha	inverting	predicted anti by clan	see at GH28
GH50	A	(β/α)8	beta	retaining	anti	4bq5	exo-β-agarase	Saccharophagus degradans	neoagarotetraose	Glu535	Glu695	[49]
GH51	A	(β/α)8	alpha	retaining	anti	1qw9	α-l-arabinofuranosidase	Geobacillus stearothermophilus	PNP-l-arabinofuranoside	Glu175	Glu294	[50]
GH52	O	(α/α)6	beta	retaining	anti	4c1p	β-xylosidase	Geobacillus thermoglucosidasius	xylobiose	Asp517	Glu537	[51]
GH53	A	(β/α)8	beta	retaining	anti	2ccr	β-1,4-galactanase	Bacillus licheniformis	galactotriose	Glu165	Glu263	[52]
GH54	none	β-sandwich	alpha	retaining	anti	1wd4	α-l-arabinofuranosidase B	Aspergillus kawachii	l-arabinofuranose	Asp297	Glu221	[53]
GH55	none	β-helix	beta	inverting	syn	4tz5	exo-β-1,3-glucanase	Streptomyces sp. SirexAA-E	laminarihexaose	Glu502	unknown	[54]
GH56	none	(β/α)7	beta	retaining	anti	1fcv	hyaluronidase	Apis mellifera	(hyaluron.)4	Glu113	internal	[55]
GH57	none	(β/α)7	alpha	retaining	anti	1k1y	glucanotransferase	Thermococcus litoralis	acarbose	Asp214	Glu123	[56]
GH59	A	(β/α)8	beta	retaining	anti	4ccc	β-galactocerebrosidase	Mus musculus	PNP-β-d-galactoside	Glu182	Glu258	[57]
GH62	F	5-fold β-propeller	alpha	unknown	predicted anti by clan	see at GH43
GH63	G	(α/α)6	alpha	inverting	anti	5ca3	α-glucosidase	Escherechia coli	glucose and lactose	Asp501	Glu727	[58]
GH65	L	(α/α)6	alpha	inverting	anti	4ktr	2-O-α-glucosylglycerol phosphorylase	Bacillus selenitireducens	isofagomine	Glu475	phosphate	[59]
GH66	none	(β/α)8	alpha	retaining	anti	5axh	dextranase	Thermoanaerobacter pseudethanolicus	isomaltohexaose	Glu374	Asp312	[60]
GH67	none	(β/α)8	alpha	inverting	syn	1l8n	α-glucuronidase	Geobacillus stearothermophilus	4-O-methyl-d-glucuronic acid and xylotriose	Glu286	Asp364 Glu392	[61]
GH68	J	5-fold β-propeller	beta	retaining	anti	1pt2	levansucrase	Bacillus subtilis	sucrose	Glu342	Asp86	[62]
GH70	H	(β/α)8	alpha	retaining	anti	3aic	glucansucrase	Streptococcus mutans	α-acarbose	Glu515	Asp477	[63]
GH72	A	(β/α)8	beta	retaining	anti	2w62	β-1,3-glucanotransferase	Saccharomyces cerevisiae S288C	laminaripentaose	Glu176	Glu275	[64]
GH74	none	7-fold β-propeller	beta	inverting	syn	2ebs	cellobiohydrolase (OXG-RCBH)	Geotrichum sp. m128	xyloglucan heptasaccharide	Asp465	Asp35	[65]
GH76	none	(α/α)6	alpha	retaining	anti	5agd	endo-α-1,6-mannanase	Bacillus circulans	α-1,6-mannopentaose	Asp125	Asp124	[66]
GH77	H	(β/α)8	alpha	retaining	anti	1esw	amylomaltase	Thermus aquaticus	acarbose	Asp395	Asp293	[67]
GH78	H	(α/α)6	alpha	inverting	anti	3w5n	α-l-rhamnosidase	Streptomyces avermitilis	l-rhamnose	Glu636	Glu895	[68]
GH79	A	(β/α)8	beta	retaining	anti	5e9c	heparanase	Homo sapiens	heparin tetrasaccharide	Glu225	Glu343	[69]
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
GH84	none	(β/α)8	beta	retaining	anti	2chn	β-N-acetyl-glucosaminidase	Bacteroides thetaiotaomicron VPI-5482	NAG-thiazoline	Glu242	internal	[70]
GH85	K	(β/α)8	beta	retaining	anti	2w92	endo-β-N-acetyl-glucosaminidase D	Streptococcus pneumoniae TIGR4	NAG-thiazoline	Glu337	internal	[71]
GH86	A	(β/α)8	beta	retaining	anti	4aw7	β-porphyranase	Bacteroides plebeius	porphyran fragment	Glu152	Glu279	[72]
GH89	none	(β/α)8	alpha	retaining	anti	2vcb	α-N-acetyl-glucosaminidase	Clostridium perfringens	PUGNAc	Glu483	Glu601	[73]
GH92	none	(α/α)6 + β-sandw.	alpha	inverting	anti	2ww1	α-1,2-mannosidase	Bacteroides thetaiotaomicron VPI-5482	thiomannobioside	Glu533	Asp644 Asp642	[74]
GH93	E	6-fold β-propeller	alpha	retaining	anti	3a72	exo-arabinanase	Penicillium chrysogenum	arabinobiose	Glu246	Glu174	[75]
GH94	none	(α/α)6	beta	inverting	syn	4zli	cellobionic acid phosphorylase	Saccharophagus degradans	3-O-β-d-glucopyranosyl-α-d-glucopyranuronic acid	Asp472	phosphate	[76]
GH95	none	(α/α)6	alpha	inverting	anti	2ead	α-1,2-l-fucosidase	Bifidobacterium bifidum	Fuc-α-1,2-Gal	Glu566	Asn423 Asp766	[77]
GH97	none	(β/α)8	alpha	retaining + inverting	anti	2zq0	α-glucosidase	Bacteroides thetaiotaomicron VPI-5482	acarbose	Glu532	Glu508	[78]
GH98	none	(β/α)8 + β-sandwich	beta	inverting	anti	2wmg	endo-β-1,4-galactosidase	Streptococcus pneumoniae	A-LewisY pentasaccharide	Glu158	Asp251 Glu301	[79]
GH99	none	(β/α)8	alpha	retaining	anti	4ad4	endo-α-mannosidase	Bacteroides xylanisolvens	glucose-1,3-isofagomine and α-1,2- mannobiose	Glu336	debated	[80]
GH100	none	(α/α)6 core	beta	inverting	anti	5gop	invertase	Anabaena (Nostoc) sp. pcc7120	sucrose	Asp188	Glu414	[81]
GH102	none	double-ψ β-barrel	beta	retaining	syn	2pi8	lytic transglycosylase A	Escherichia coli	chitohexaose	Asp308	none	[82]
GH103	none	lysozyme type	beta	retaining	syn	1d0k	lytic transglycosylase SLT35	Escherichia coli	murodipeptides	Glu162	internal	[83]
GH106	none	(β/α)8	alpha	inverting	anti	5mwk	α-l-rhamnosidase BT_0986	Bacteroides thetaiotaomicron	pectin heptasaccharide	Glu461	Glu593 or Glu561	[84]
GH113	A	(β/α)8	beta	retaining	anti	4cd8	β-mannanase	Alicyclobacillus acidocaldarius	mannobioimidazole	Glu151	Glu231	[85]
GH116	O	β-sandwich + (α/α)6	beta	retaining	predicted anti by clan	see at GH52
GH117	none	5-fold β-propeller	alpha	inverting	anti	4ak7	α-1,3-3,6-anhydro-l-galactosidase	Bacteroides plebeius	neoagarobiose	His302	Asp90	[86]
GH123	none	(β/α)8 + β-sandwich	beta	retaining	anti	5fr0	exo-β-N-acetyl-galactosaminidase	Clostridium perfringens	N-difluoroacetyl-d-galactosamine	Glu345	internal	[87]
GH125	L	(α/α)6	alpha	inverting	anti	5m7y	exo-α-1,6-mannosidase	Clostridium perfringens	1,6-α-mannotriose	Asp220	Glu393	[88]
GH127	none	(α/α)6 + β-sandwich	beta	retaining	anti	3wrg	β-l-arabinofuranosidase	Bifidobacterium longum	l-arabinose	Glu322	Cys417	[89]
GH128	A	(β/α)8	beta	retaining	predicted anti by clan	see e.g. at GH1
GH130	none	5-fold β-propeller	beta	inverting	anti	5b0s	β-1,2-mannobiose phosphorylase	Listeria innocua	β-1,2-mannotriose	Asp141-relay	phosphate	[90]
GH134	none	β + α	beta	inverting	syn	5jug	β-mannanase	Streptomyces sp.	mannopentaose	Glu45	Asp57	[91]
GH137	none	5-fold β-propeller	beta	unknown	anti	5mui	β-l-arabinofuranosidase BT_0996	Bacteroides thetaiotaomicron	pectin oligosaccharide	Glu240	Glu159	[84]

References

Error fetching PMID 15642336:
Error fetching PMID 23137336:
Error fetching PMID 19733839:
Error fetching PMID 17002288:
Error fetching PMID 18976664:
Error fetching PMID 12595701:
Error fetching PMID 17666401:
Error fetching PMID 11884144:
Error fetching PMID 14756552:
Error fetching PMID 19279191:
Error fetching PMID 24419374:
Error fetching PMID 12741813:
Error fetching PMID 8431441:
Error fetching PMID 15062085:
Error fetching PMID 11560481:
Error fetching PMID 10884356:
Error fetching PMID 15299731:
Error fetching PMID 8259514:
Error fetching PMID 20592022:
Error fetching PMID 22451675:
Error fetching PMID 17335500:
Error fetching PMID 23015718:
Error fetching PMID 23012371:
Error fetching PMID 18599462:
Error fetching PMID 20739278:
Error fetching PMID 17905739:
Error fetching PMID 15299721:
Error fetching PMID 24766439:
Error fetching PMID 23921382:
Error fetching PMID 14517232:
Error fetching PMID 19089956:
Error fetching PMID 25752603:
Error fetching PMID 11080624:
Error fetching PMID 24297913:
Error fetching PMID 27688023:
Error fetching PMID 24828502:
Error fetching PMID 26494689:
Error fetching PMID 17498741:
Error fetching PMID 25772148:
Error fetching PMID 11082203:
Error fetching PMID 26575439:
Error fetching PMID 23150581:
Error fetching PMID 21543843:
Error fetching PMID 26041776:
Error fetching PMID 24582745:
Error fetching PMID 22219371:
Error fetching PMID 27777307:
Error fetching PMID 22393053:
Error fetching PMID 27038508:
Error fetching PMID 28026180:
Error fetching PMID 26632508:

1. Heightman TD and Vasella AT. Recent Insights into Inhibition, Structure, and Mechanism of Configuration-Retaining Glycosidases. Angew Chem Int Ed. 1999 38(6):750-770. Article online.

4. Pérez S and Marchessault RH. The exo-anomeric effect: experimental evidence from crystal structures. Carbohydr res. 1978 65:114-120. DOI:10.1016/S0008-6215(00)84218-4

5. Cramer CJ, Truhlar DG, and French AD. Exo-anomeric effects on energies and geometries of different conformations of glucose and related systems in the gas phase and aqueous solution. Carbohydr res. 1997 298:1-14. DOI:10.1016/S0008-6215(96)00297-2

9. 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 |
11. Zou Jy, Kleywegt GJ, Ståhlberg J, Driguez H, Nerinckx W, Claeyssens M, Koivula A, Teeri TT, and Jones TA. (1999). Crystallographic evidence for substrate ring distortion and protein conformational changes during catalysis in cellobiohydrolase Ce16A from trichoderma reesei. Structure. 1999;7(9):1035-45. DOI:10.1016/s0969-2126(99)80171-3 |
12. 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 |
17. Sandgren M, Berglund GI, Shaw A, Ståhlberg J, Kenne L, Desmet T, and Mitchinson C. (2004). Crystal complex structures reveal how substrate is bound in the -4 to the +2 binding sites of Humicola grisea Cel12A. J Mol Biol. 2004;342(5):1505-17. DOI:10.1016/j.jmb.2004.07.098 |
18. 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 |
25. 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 |
28. Cartmell A, Topakas E, Ducros VM, Suits MD, Davies GJ, and Gilbert HJ. (2008). The Cellvibrio japonicus mannanase CjMan26C displays a unique exo-mode of action that is conferred by subtle changes to the distal region of the active site. J Biol Chem. 2008;283(49):34403-13. DOI:10.1074/jbc.M804053200 |
30. Abbott DW and Boraston AB. (2007). The structural basis for exopolygalacturonase activity in a family 28 glycoside hydrolase. J Mol Biol. 2007;368(5):1215-22. DOI:10.1016/j.jmb.2007.02.083 |
33. Sim L, Quezada-Calvillo R, Sterchi EE, Nichols BL, and Rose DR. (2008). Human intestinal maltase-glucoamylase: crystal structure of the N-terminal catalytic subunit and basis of inhibition and substrate specificity. J Mol Biol. 2008;375(3):782-92. DOI:10.1016/j.jmb.2007.10.069 |
35. Amaya MF, Watts AG, Damager I, Wehenkel A, Nguyen T, Buschiazzo A, Paris G, Frasch AC, Withers SG, and Alzari PM. (2004). Structural insights into the catalytic mechanism of Trypanosoma cruzi trans-sialidase. Structure. 2004;12(5):775-84. DOI:10.1016/j.str.2004.02.036 |
37. Maksimainen M, Hakulinen N, Kallio JM, Timoharju T, Turunen O, and Rouvinen J. (2011). Crystal structures of Trichoderma reesei β-galactosidase reveal conformational changes in the active site. J Struct Biol. 2011;174(1):156-63. DOI:10.1016/j.jsb.2010.11.024 |
39. 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 |
41. Czjzek M, Ben David A, Bravman T, Shoham G, Henrissat B, and Shoham Y. (2005). Enzyme-substrate complex structures of a GH39 beta-xylosidase from Geobacillus stearothermophilus. J Mol Biol. 2005;353(4):838-46. DOI:10.1016/j.jmb.2005.09.003 |
42. Godoy AS, Camilo CM, Kadowaki MA, Muniz HD, Espirito Santo M, Murakami MT, Nascimento AS, and Polikarpov I. (2016). Crystal structure of β1→6-galactosidase from Bifidobacterium bifidum S17: trimeric architecture, molecular determinants of the enzymatic activity and its inhibition by α-galactose. FEBS J. 2016;283(22):4097-4112. DOI:10.1111/febs.13908 |
47. 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 |
48. 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 |
51. Espina G, Eley K, Pompidor G, Schneider TR, Crennell SJ, and Danson MJ. (2014). A novel β-xylosidase structure from Geobacillus thermoglucosidasius: the first crystal structure of a glycoside hydrolase family GH52 enzyme reveals unpredicted similarity to other glycoside hydrolase folds. Acta Crystallogr D Biol Crystallogr. 2014;70(Pt 5):1366-74. DOI:10.1107/S1399004714002788 |
53. Miyanaga A, Koseki T, Matsuzawa H, Wakagi T, Shoun H, and Fushinobu S. (2004). Crystal structure of a family 54 alpha-L-arabinofuranosidase reveals a novel carbohydrate-binding module that can bind arabinose. J Biol Chem. 2004;279(43):44907-14. DOI:10.1074/jbc.M405390200 |
56. 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 |
61. Golan G, Shallom D, Teplitsky A, Zaide G, Shulami S, Baasov T, Stojanoff V, Thompson A, Shoham Y, and Shoham G. (2004). Crystal structures of Geobacillus stearothermophilus alpha-glucuronidase complexed with its substrate and products: mechanistic implications. J Biol Chem. 2004;279(4):3014-24. DOI:10.1074/jbc.M310098200 |
62. Meng G and Fütterer K. (2003). Structural framework of fructosyl transfer in Bacillus subtilis levansucrase. Nat Struct Biol. 2003;10(11):935-41. DOI:10.1038/nsb974 |
63. Ito K, Ito S, Shimamura T, Weyand S, Kawarasaki Y, Misaka T, Abe K, Kobayashi T, Cameron AD, and Iwata S. (2011). Crystal structure of glucansucrase from the dental caries pathogen Streptococcus mutans. J Mol Biol. 2011;408(2):177-86. DOI:10.1016/j.jmb.2011.02.028 |
64. Hurtado-Guerrero R, Schüttelkopf AW, Mouyna I, Ibrahim AF, Shepherd S, Fontaine T, Latgé JP, and van Aalten DM. (2009). Molecular mechanisms of yeast cell wall glucan remodeling. J Biol Chem. 2009;284(13):8461-9. DOI:10.1074/jbc.M807990200 |
68. Fujimoto Z, Jackson A, Michikawa M, Maehara T, Momma M, Henrissat B, Gilbert HJ, and Kaneko S. (2013). The structure of a Streptomyces avermitilis α-L-rhamnosidase reveals a novel carbohydrate-binding module CBM67 within the six-domain arrangement. J Biol Chem. 2013;288(17):12376-85. DOI:10.1074/jbc.M113.460097 |
70. Dennis RJ, Taylor EJ, Macauley MS, Stubbs KA, Turkenburg JP, Hart SJ, Black GN, Vocadlo DJ, and Davies GJ. (2006). Structure and mechanism of a bacterial beta-glucosaminidase having O-GlcNAcase activity. Nat Struct Mol Biol. 2006;13(4):365-71. DOI:10.1038/nsmb1079 |
71. Abbott DW, Macauley MS, Vocadlo DJ, and Boraston AB. (2009). Streptococcus pneumoniae endohexosaminidase D, structural and mechanistic insight into substrate-assisted catalysis in family 85 glycoside hydrolases. J Biol Chem. 2009;284(17):11676-89. DOI:10.1074/jbc.M809663200 |
73. Ficko-Blean E, Stubbs KA, Nemirovsky O, Vocadlo DJ, and Boraston AB. (2008). Structural and mechanistic insight into the basis of mucopolysaccharidosis IIIB. Proc Natl Acad Sci U S A. 2008;105(18):6560-5. DOI:10.1073/pnas.0711491105 |
74. Zhu Y, Suits MD, Thompson AJ, Chavan S, Dinev Z, Dumon C, Smith N, Moremen KW, Xiang Y, Siriwardena A, Williams SJ, Gilbert HJ, and Davies GJ. (2010). Mechanistic insights into a Ca2+-dependent family of alpha-mannosidases in a human gut symbiont. Nat Chem Biol. 2010;6(2):125-32. DOI:10.1038/nchembio.278 |
77. 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 |
78. Kitamura M, Okuyama M, Tanzawa F, Mori H, Kitago Y, Watanabe N, Kimura A, Tanaka I, and Yao M. (2008). Structural and functional analysis of a glycoside hydrolase family 97 enzyme from Bacteroides thetaiotaomicron. J Biol Chem. 2008;283(52):36328-37. DOI:10.1074/jbc.M806115200 |
79. Higgins MA, Whitworth GE, El Warry N, Randriantsoa M, Samain E, Burke RD, Vocadlo DJ, and Boraston AB. (2009). Differential recognition and hydrolysis of host carbohydrate antigens by Streptococcus pneumoniae family 98 glycoside hydrolases. J Biol Chem. 2009;284(38):26161-73. DOI:10.1074/jbc.M109.024067 |
82. van Straaten KE, Barends TR, Dijkstra BW, and Thunnissen AM. (2007). Structure of Escherichia coli Lytic transglycosylase MltA with bound chitohexaose: implications for peptidoglycan binding and cleavage. J Biol Chem. 2007;282(29):21197-205. DOI:10.1074/jbc.M701818200 |
83. van Asselt EJ, Kalk KH, and Dijkstra BW. (2000). Crystallographic studies of the interactions of Escherichia coli lytic transglycosylase Slt35 with peptidoglycan. Biochemistry. 2000;39(8):1924-34. DOI:10.1021/bi992161p |
84. Ndeh D, Rogowski A, Cartmell A, Luis AS, Baslé A, Gray J, Venditto I, Briggs J, Zhang X, Labourel A, Terrapon N, Buffetto F, Nepogodiev S, Xiao Y, Field RA, Zhu Y, O'Neil MA, Urbanowicz BR, York WS, Davies GJ, Abbott DW, Ralet MC, Martens EC, Henrissat B, and Gilbert HJ. (2017). Complex pectin metabolism by gut bacteria reveals novel catalytic functions. Nature. 2017;544(7648):65-70. DOI:10.1038/nature21725 |
85. Williams RJ, Iglesias-Fernández J, Stepper J, Jackson A, Thompson AJ, Lowe EC, White JM, Gilbert HJ, Rovira C, Davies GJ, and Williams SJ. (2014). Combined inhibitor free-energy landscape and structural analysis reports on the mannosidase conformational coordinate. Angew Chem Int Ed Engl. 2014;53(4):1087-91. DOI:10.1002/anie.201308334 |

89. Huang CH, Zhu Z, Cheng YS, Chan HC, Ko TP, Chen CC, Wang I, Ho MR, Hsu ST, Zeng YF, Huang YN, Liu JR, Guo RT. Structure and Catalytic Mechanism of a Glycoside Hydrolase Family-127 β-L-Arabinofuranosidase (HypBA1). J Bioprocess Biotech. 2014 4:171 DOI:10.4172/2155-9821.1000171

91. Jin Y, Petricevic M, John A, Raich L, Jenkins H, Portela De Souza L, Cuskin F, Gilbert HJ, Rovira C, Goddard-Borger ED, Williams SJ, and Davies GJ. A β-Mannanase with a Lysozyme-like Fold and a Novel Molecular Catalytic Mechanism. ACS Cent Sci. 2016 Nov DOI:10.1021/acscentsci.6b00232