Glycoside Hydrolase Family 3

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.

• Authors: ^^^Geoff Fincher^^^ and ^^^Brian Mark^^^
• Responsible Curator: ^^^Bernard Henrissat^^^

---

Glycoside Hydrolase Family GH3
Clan	none
Mechanism	retaining
Active site residues	known
CAZy DB link
https://www.cazy.org/GH3.html

Substrate specificities

The GH3 glycoside hydrolase family currently group together β-D-glucosidases, α-L-arabinofuranosidases, β-D-xylopyranosidases and N-acetyl-β-D-glucosaminidases [1]. Widely distributed in bacteria, fungi and plants, GH3 enzymes carry out a range of functions including cellulosic biomass degradation, plant and bacterial cell wall remodeling, energy metabolism and pathogen defense. In many cases the enzymes have dual or broad substrate specificities with respect to monosaccharide residues, linkage position and chain length of the substrate. For example, there are several well-characterized ‘bifunctional’ enzymes in the family that have both α-L-arabinofuranosidase and β-D-xylopyranosidase activity [2], and one characterized example of an N-acetyl-β-D-glucosaminidase/β-glucosidase from Cellulomonas fimi (Nag3) [3]. GH3 β-D-glucosidases from barley, which are more precisely referred to as β-D-glucan glucohydrolases, are also broad specificity exo-hydrolases that remove single glucosyl residues from the non-reducing ends of a range of β-D-glucans, β-D-oligoglucosides and aryl β-D-glucosides, including (1,3)-β-D-glucans, (1,4)-β-D-glucans, (1,3;1,4)-β-D-glucans and (1,6)-β-D-glucans, 4-nitrophenyl β-D-glucoside, certain cyanogenic β-D-glucosides and some β-D-oligoxyloglucosides [4].

Figure 1. Phylogeny of plant GH3 glycoside hydrolases. Plant GH3 enzymes separate into two major groups that are shown here as the ‘β-glucosidase’ clade and a ‘non- β-glucosidase’ clade. Whether or not all enzymes in the two clades actually have distinct substrate specificities remains to be demonstrated. Dicot GH3 enzymes are shown in red, monocots in blue and purple, and lower plants in green.

In contrast to the broad substrate specificities observed for the GH3 enzymes described above, GH3 N-acetyl-β-D-glucosaminidases are selective for N-acetyl-β-D-glucosamine (GlcNAc) [5] (though exceptions exist such as Cellulomonas fimi Nag3 [3]). A notable GH3 N-acetyl-β-D-glucosaminidase of prokaryotes is NagZ, which participates in bacterial cell wall recycling (for review see [6]) by removing GlcNAc from 1,6-anhydroMurNAc-peptides in Gram-negative bacteria [7], or GlcNAc from GlcNAc-MurNAc-peptides in Gram-positive bacteria [8]. The NagZ product 1,6-anhydroMurNAc-peptide is an important activator of AmpC β-lactamase hyper-production in several Gram-negative pathogens, making the enzyme of interest as a potential therapeutic target [9].

As more plant genome sequences are published, it is becoming clear that the GH3 glycoside hydrolases in plants are encoded by multi-gene families. In both monocot and dicot species, there are 15-18 genes for the GH3 enzymes, while in lower plants such as the Physcomitrella and Selaginella mosses 6-7 genes encoding GH3 glycoside hydrolases have been identified. Furthermore, phylogenetic analyses of the plant GH3 enzymes reveal their separation into two major groups (Fig. 1). Existing annotations suggest that one plant group might include β-D-glucosidases and the other α-L-arabinofuranosidases, β-D-xylopyranosidase and other enzymes. However, this suggestion is limited to plant GH3 enzymes and must be viewed with caution until further confirmation is obtained, because relatively few members of the enzyme family have been purified for detailed characterization of their substrate specificities. There do not appear to be any confirmed plant β-N-acetylglucosaminidases in either clade.

Kinetics and Mechanism

Figure 2. Ribbon representation of barley β-glucan exohydrolase isoenzyme ExoI. Domain 1, domain 2, and the linker region of the enzyme are coloured in magenta, cyan, and yellow, respectively. Figure from [1].

GH3 glycoside hydrolases remove single glycosyl residues from the non-reducing ends of their substrates. Catalysis occurs via a classical Koshland double-displacement mechanism with the β-anomeric configuration of the released glycose being retained. The retention of anomeric configuration has been established experimentally for several enzymes (Which? And how?). The active site of GH3 enzymes consists of two glucosyl-binding subsites (-1 and +1) with an enzymic nucleophile and general acid/base residue flanking the junction of these two subsites (see [10] for subsite nomenclature). This arrangement of catalytic residues was first visualized in 1999 when the crystal structure of barley β-D-glucan glucohydrolase was determined in complex with glucose [11] (Fig. 2).

Several studies have contributed to the understanding of the kinetics and mechanism of GH3 enzymes, including detailed analyses of β-glucosidases from fungi (Aspergillus wentii [12] and Aspergillus niger [13, 14]) and Gram-negative bacteria (Flavobacterium meningosepticum [15, 16], Thermotoga neapolitana [17]), as well as a GH3 glucosylceramidase from the Gram-positive microbe Paenibacillus sp. TS12 [18]. Kinetic and mechanistic analyses of β-D-glucan glucohydrolases and two ‘bifunctional’ α-L-arabinofuranosidase/β-D-xylopyranosidases from plants (barley) have also been carried out [2, 4]. These studies, combined with kinetic and mechanistic analyses of N-acetyl-β-D-glucosaminidases from the Gram-positive microbe Bacilus subtillus [8, 19], and Gram-negative microbes Vibrio furnisii [20, 21], Vibrio cholerea [22] and Salmonella typhimerium [19] confirm that while the catalytic nucleophile of GH3 enzymes is well conserved, the location and identity of the general acid/base residue is not.

Catalytic Residues

Catalytic nucleophile

Figure 3. Overlay of barley β-glucan exohydrolase isoenzyme ExoI with other known X-ray structures of multi-domain β-glucosidases. While additional domains may be present (not shown for clarity), the core two-domain architecture observed for Exo1 and the unusual two-domain active site architecture (Asp nucleophile on domain 1 and general acid/base on domain 2) appears to be a structurally conserved feature of multidomain GH3 β-glucanases. Colour coding: Exo1 domain 1 (magenta) and domain 2 (cyan) bound to thiocellobiose (salmon) (PDB 1IEX); Pseudoalteromonas sp. Exo-1,3/1,4-b-glucanase ExoP (grey) (PDB 3UTO); Thermotoga neapolitan β-glucosidase 3B Bgl3B (orange) (PDB 2X41); Kluyveromyces marxianus β-glucosidase KmBgl1 (yellow) (PDB 3ACO); Hypocrea jecorina β-glucosidase Bgl1 (green) (PDB 3ZYZ); Streptomyces venezuelae β-glucosidase DesR (blue) (PDB 4I3G).

Figure 4. Overlay of barley β-glucan exohydrolase isoenzyme ExoI (domain 1 in magenta, and domain 2 in cyan) with the two-domain GH3 NagZ from B. subtilis (BsNagZ) (yellow) (PDB 3BMX). GH3 NagZ enzymes contain a conserved histidine/aspartate dyad within a flexible loop of the catalytic domain that has been proposed as the general acid/base. In contrast to Exo1, the additional domain of BsNagZ does not participate in catalysis. The catalytic Asp nucleophile however, is conserved across the GH3 family, including the NagZ enzymes.

Figure 5. Overlay of Bacillus subtilis NagZ (BsNagZ) (yellow) (PDB 3BMX) with a single-domain NagZ from the Gram-negative microbe Burkholderia cenocepacia (BcNagZ) (blue) bound to GlcNAc (green) (PDB 4GNV). The majority of NagZ enzymes encoded by Gram-negative bacteria are single domain enzymes that use a putative histidine/aspartate dyad as the catalytic acid/base, as first described for BsNagZ [23].

Early labeling experiments of a GH3 β-glucosidase from Aspergillus wentii using conduritol B-epoxide by Bause and Legler in 1974 [12] identified an aspartate residue within the sequence VMSDW as the putative catalytic nucleophile. This was later supported by the crystal structure of barley β-D-glucan glucohydrolase, which identified Asp285 within the sequence GFVISDW as being appropriately positioned to act as a nucleophile during catalysis [11]. Direct identification of this aspartate as the catalytic nucleophile via active-site labeling using 2-deoxy-2-fluoro-β-D-glycosides of GH3 β-glucosidases from A. niger [13] and F. meningosepticum [15], a glucosylceramidase from Paenibacillus sp [18], as well as the barley β-D-glucan glucohydrolase [24], and labeling of NagZ enzymes from V. furnisii [20] and S. typhimerium [19] using 2-acetamido-2-deoxy-5-fluoro-β-D-glucopyranosyl fluoride, have confirmed that this catalytic residue is well conserved in GH3 enzymes from diverse species. The conservation of this aspartate becomes clear when known crystal structures of a number of GH3 enzymes are superposed (Fig. 3).

Catalytic acid/base

Though sequence alignments can now be used to easily identify the catalytic nucleophile of GH3 members, the position of the general acid/base residue is phylogenetically variable and less readily identifiable [14]. Detailed kinetic analyses and an increase in 3D structural information continues to provide insight into identity of the elusive general acid-base residue across the diversity of GH3 members.

The seminal structural study of the barley β-D-glucan glucohydrolase ExoI, in complex with the product glucose, was the first to suggest the identity of the catalytic acid base in a GH3 member. Barley ExoI is a two-domain enzyme consisting of an N-terminal (b/a)₈ barrel domain housing the active site pocket and the catalytic nucleophile (Asp285). The C-terminal domain contains a glutamate residue (Glu 491) projecting into the active site of the (b/a)₈ barrel domain, which was proposed to act as the catalytic acid/base [11]. These assignments were also supported by crystallography of pseudo-Michaelis complexes with non-hydrolyzable thio-glycosides [24, 25].

Kinetic analysis, including the use of site-directed mutation and chemical rescue, have been used to provide early experimental support for the identification of the catalytic acid/base in several bacterial and fungal GH3 members: Flavobacterium meningosepticum beta-glucosidase [16], Paenibacillus sp. TS12 glucosylceramidase [18], Thermotoga neapolitana beta-glucosidase [17], and Aspergillus niger beta-glucosidase [14]. The identification of Glu-473 as the catalytic acid/base in the F. meningosepticum enzyme was further supported by covalent labelling with N-bromoacetyl-beta-D-glucosylamine and peptide mass spectrometry [15].

Later structural studies of bacterial and fungal GH3 enzymes have since shown that while insertion of additional domains is possible (which shifts the location of the glutamic acid general acid-base within the primary sequence), the contribution of two-domains to the active site architecture, as first observed for the barley enzyme, appears to be a core feature of multidomain GH3 b-glucanases [17, 26, 27]. Superposition of available GH3 β-D-glucan glucohydrolase structures clearly reveals the conservation of this architecture, and directly highlights active-site residue homology in the absence of protein sequence similarity - especially in the case of the catalytic acid-base [14] (Fig. 3).

Notably, GH3 NagZ enzymes represent a significant departure from the above two-domain active site architecture paradigm. A crystal structure of NagZ from B. subtilis, together with kinetic analysis, recently revealed that the catalytic acid-base is an unusual histidine/aspartate dyad that resides within a flexible loop on the catalytic (b/a)₈ barrel, not on a separate domain [23]. Though the enzyme adopts a two-domain fold similar to the barely β-D-glucan glucohydrolase, the C-terminal domain does not participate in catalysis (Fig. 4). In fact, most NagZ enzymes from Gram-negative bacteria are single domain enzymes comprised solely of a catalytic (b/a)₈ barrel that contains the conserved aspartate nucleophile and a catalytic histidine/aspartate dyad on flexible loop, as seen for B. subtilis NagZ [19] (Fig. 5). The flexible loop containing the His/Asp dyad is unique to GH3 NagZ enzymes and can be identified by the consensus motif [KH(F/I)PG(H/L)GXXXXD(S/T)H] (catalytic dyad highlighted in boldface) [20].

Three-dimensional structures

Figure 6. The conserved loop containing the proposed catalytic acid/base histidine of GH3 NagZ enzymes is highly mobile, which appears to drive substrate distortion to promote glycosidic bond hydrolysis[19]. Colour scheme: B. subtilis NagZ (BsNagZ) (yellow) (PDB 4GYJ and 4GYK), S. typhimurium NagZ (StNagZ) (grey)(PDB 4GVF).

Crystal structures are now available for a number of multidomain GH3 members, including barley β-D-glucan glucohydrolase [11] and a mechanistically related β-glucanase from the marine bacterium Pseudoalteromonas sp. [26], as well as β-glucosidases from Kluyveromyces marxianus (KmBglI) [27] , Trichoderma reesei (Cel3A) (PDB 4I8D (unpublished)), Thermotoga neapolitana [17] and a macrolide β-glycosidase / β-glucosidase (DesR) from Streptomyces venezuelae [28] (please see the GH3 structure page of the CAZy DB for a continuously updated list). These structures have revealed considerable diversity in architecture and arrangement of domains in GH3 enzymes that are present in addition to the core catalytic domain, and have provided insight into how these domains affect function.

Crystal structures of a number of NagZ enzymes are also available, including the two-domain NagZ from B. subtilis [23] and single domain NagZ enzymes from Vibrio cholera (PDB 1TR9 (unpublished)) & [22], S. typhimurium [19], Deinococcus radiodurans (PDB 3TEV (unpublished)) and Burkholderia cenocepacia (PDB 4GNV (unpublished)). Given the role of NagZ in the activation of AmpC-mediated β-lactam resistance in Gram-negative bacteria [9], a number of crystallographic and kinetic studies have focused on the development of small-molecule inhibitors of NagZ [22, 29, 30], some of which have been designed to be selective for GH3 NagZ over functionally related human enzymes from families GH20 and GH84 [22, 29].

Insight into the broad specificity observed for some GH3 enzymes has been provided from X-ray crystallographic data and from molecular modeling of enzyme-substrate complexes of the barley β-D-glucan glucohydrolase [11, 25]. Recent structural studies of NagZ enzymes from S. typhimurium and B. subtilis have shown the flexible catalytic loop participates in distorting the bound terminal GlcNAc sugar toward a ¹S₃ conformation during catalysis [19] (Fig. 6). Distortion of the substrate toward a ¹S₃ conformation is in agreement with other retaining β-glycosidases; however, this has not been observed for other GH3 enzymes.

Family Firsts

First sterochemistry determination

To be added.

First catalytic nucleophile identification

First suggested by Bause and Legler in 1974 using conduritol B-epoxide labelling of an Aspergillus wentii glucosidase [12], and later supported by the crystal structures of a product complex of a barley β-D-glucan glucohydrolase [11] and a trapped covalent intermediate [24]. Contemporaneous active-site labeling of an A. niger β-glucosidase [13] and V. furnisii NagZ [20] using 2-deoxy-2-fluoro-β-D-glycosides allowed unequivocal identification of the catalytic nucleophiles in these enzymes.

First general acid/base identification

In contrast to the catalytic nucleophile, the catalytic acid/base is not broadly conserved on the protein sequence level; thus, the "first" identification was not strictly definitive in this family (this living history is detailed above). The GH3 general acid/base was first suggested by a product complex of a barley β-D-glucan glucohydrolase [11] (and later by other complex structures of this same enzyme [24, 25]). The earliest definitive kinetic studies were performed on a Flavobacterium meningosepticum beta-glucosidase [15, 16]. The first revelation of the atypical Asp/His dyad fulfilling this role was for B. subtilis NagZ [8].

First 3-D structure

The first 3D structure in family GH3 was that of the two-domain barley β-D-glucan glucohydrolase [11]. As discussed above, the number and organization of domains among GH3 members is diverse, such that a number of seminal structures could be highlighted.

References

1. Harvey AJ, Hrmova M, De Gori R, Varghese JN, and Fincher GB. (2000). Comparative modeling of the three-dimensional structures of family 3 glycoside hydrolases. Proteins. 2000;41(2):257-69. DOI:10.1002/1097-0134(20001101)41:2<257::aid-prot100>3.0.co;2-c |
2. Lee RC, Hrmova M, Burton RA, Lahnstein J, and Fincher GB. (2003). Bifunctional family 3 glycoside hydrolases from barley with alpha -L-arabinofuranosidase and beta -D-xylosidase activity. Characterization, primary structures, and COOH-terminal processing. J Biol Chem. 2003;278(7):5377-87. DOI:10.1074/jbc.M210627200 |
3. Mayer C, Vocadlo DJ, Mah M, Rupitz K, Stoll D, Warren RA, and Withers SG. (2006). Characterization of a beta-N-acetylhexosaminidase and a beta-N-acetylglucosaminidase/beta-glucosidase from Cellulomonas fimi. FEBS J. 2006;273(13):2929-41. DOI:10.1111/j.1742-4658.2006.05308.x |

4. Hrmova, M. and Fincher, G.B. (1998) Barley ß-D-glucan exohydrolases. Substrate specificity and kinetic properties. Carbohydr. Res. 305, 209-221.

5. Chitlaru E and Roseman S. (1996). Molecular cloning and characterization of a novel beta-N-acetyl-D-glucosaminidase from Vibrio furnissii. J Biol Chem. 1996;271(52):33433-9. DOI:10.1074/jbc.271.52.33433 |
6. Johnson JW, Fisher JF, and Mobashery S. (2013). Bacterial cell-wall recycling. Ann N Y Acad Sci. 2013;1277(1):54-75. DOI:10.1111/j.1749-6632.2012.06813.x |
7. Cheng Q, Li H, Merdek K, and Park JT. (2000). Molecular characterization of the beta-N-acetylglucosaminidase of Escherichia coli and its role in cell wall recycling. J Bacteriol. 2000;182(17):4836-40. DOI:10.1128/JB.182.17.4836-4840.2000 |
8. Litzinger S, Duckworth A, Nitzsche K, Risinger C, Wittmann V, and Mayer C. (2010). Muropeptide rescue in Bacillus subtilis involves sequential hydrolysis by beta-N-acetylglucosaminidase and N-acetylmuramyl-L-alanine amidase. J Bacteriol. 2010;192(12):3132-43. DOI:10.1128/JB.01256-09 |
9. Mark BL, Vocadlo DJ, and Oliver A. (2011). Providing β-lactams a helping hand: targeting the AmpC β-lactamase induction pathway. Future Microbiol. 2011;6(12):1415-27. DOI:10.2217/fmb.11.128 |
10. Davies GJ, Wilson KS, and Henrissat B. (1997). Nomenclature for sugar-binding subsites in glycosyl hydrolases. Biochem J. 1997;321 ( Pt 2)(Pt 2):557-9. DOI:10.1042/bj3210557 |
11. Varghese JN, Hrmova M, and Fincher GB. (1999). Three-dimensional structure of a barley beta-D-glucan exohydrolase, a family 3 glycosyl hydrolase. Structure. 1999;7(2):179-90. DOI:10.1016/s0969-2126(99)80024-0 |
12. Bause E and Legler G. (1974). Isolation and amino acid sequence of a hexadecapeptide from the active site of beta-glucosidase A3 from Aspergillus wentii. Hoppe Seylers Z Physiol Chem. 1974;355(4):438-42. DOI:10.1515/bchm2.1974.355.1.438 |
13. Dan S, Marton I, Dekel M, Bravdo BA, He S, Withers SG, and Shoseyov O. (2000). Cloning, expression, characterization, and nucleophile identification of family 3, Aspergillus niger beta-glucosidase. J Biol Chem. 2000;275(7):4973-80. DOI:10.1074/jbc.275.7.4973 |
14. Thongpoo P, McKee LS, Araújo AC, Kongsaeree PT, and Brumer H. (2013). Identification of the acid/base catalyst of a glycoside hydrolase family 3 (GH3) beta-glucosidase from Aspergillus niger ASKU28. Biochim Biophys Acta. 2013;1830(3):2739-49. DOI:10.1016/j.bbagen.2012.11.014 |
15. Chir J, Withers S, Wan CF, and Li YK. (2002). Identification of the two essential groups in the family 3 beta-glucosidase from Flavobacterium meningosepticum by labelling and tandem mass spectrometric analysis. Biochem J. 2002;365(Pt 3):857-63. DOI:10.1042/BJ20020186 |
16. Li YK, Chir J, Tanaka S, and Chen FY. (2002). Identification of the general acid/base catalyst of a family 3 beta-glucosidase from Flavobacterium meningosepticum. Biochemistry. 2002;41(8):2751-9. DOI:10.1021/bi016049e |
17. Pozzo T, Pasten JL, Karlsson EN, and Logan DT. (2010). Structural and functional analyses of beta-glucosidase 3B from Thermotoga neapolitana: a thermostable three-domain representative of glycoside hydrolase 3. J Mol Biol. 2010;397(3):724-39. DOI:10.1016/j.jmb.2010.01.072 |
18. Paal K, Ito M, and Withers SG. (2004). Paenibacillus sp. TS12 glucosylceramidase: kinetic studies of a novel sub-family of family 3 glycosidases and identification of the catalytic residues. Biochem J. 2004;378(Pt 1):141-9. DOI:10.1042/BJ20031028 |
19. Bacik JP, Whitworth GE, Stubbs KA, Vocadlo DJ, and Mark BL. (2012). Active site plasticity within the glycoside hydrolase NagZ underlies a dynamic mechanism of substrate distortion. Chem Biol. 2012;19(11):1471-82. DOI:10.1016/j.chembiol.2012.09.016 |
20. Vocadlo DJ, Mayer C, He S, and Withers SG. (2000). Mechanism of action and identification of Asp242 as the catalytic nucleophile of Vibrio furnisii N-acetyl-beta-D-glucosaminidase using 2-acetamido-2-deoxy-5-fluoro-alpha-L-idopyranosyl fluoride. Biochemistry. 2000;39(1):117-26. DOI:10.1021/bi991958d |
21. Vocadlo DJ and Withers SG. (2005). Detailed comparative analysis of the catalytic mechanisms of beta-N-acetylglucosaminidases from families 3 and 20 of glycoside hydrolases. Biochemistry. 2005;44(38):12809-18. DOI:10.1021/bi051121k |
22. Stubbs KA, Balcewich M, Mark BL, and Vocadlo DJ. (2007). Small molecule inhibitors of a glycoside hydrolase attenuate inducible AmpC-mediated beta-lactam resistance. J Biol Chem. 2007;282(29):21382-91. DOI:10.1074/jbc.M700084200 |
23. Litzinger S, Fischer S, Polzer P, Diederichs K, Welte W, and Mayer C. (2010). Structural and kinetic analysis of Bacillus subtilis N-acetylglucosaminidase reveals a unique Asp-His dyad mechanism. J Biol Chem. 2010;285(46):35675-84. DOI:10.1074/jbc.M110.131037 |
24. 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 |
25. Hrmova M, De Gori R, Smith BJ, Fairweather JK, Driguez H, Varghese JN, and Fincher GB. (2002). Structural basis for broad substrate specificity in higher plant beta-D-glucan glucohydrolases. Plant Cell. 2002;14(5):1033-52. DOI:10.1105/tpc.010442 |
26. Nakatani Y, Cutfield SM, Cowieson NP, and Cutfield JF. (2012). Structure and activity of exo-1,3/1,4-β-glucanase from marine bacterium Pseudoalteromonas sp. BB1 showing a novel C-terminal domain. FEBS J. 2012;279(3):464-78. DOI:10.1111/j.1742-4658.2011.08439.x |
27. Yoshida E, Hidaka M, Fushinobu S, Koyanagi T, Minami H, Tamaki H, Kitaoka M, Katayama T, and Kumagai H. (2010). Role of a PA14 domain in determining substrate specificity of a glycoside hydrolase family 3 β-glucosidase from Kluyveromyces marxianus. Biochem J. 2010;431(1):39-49. DOI:10.1042/BJ20100351 |
28. Zmudka MW, Thoden JB, and Holden HM. (2013). The structure of DesR from Streptomyces venezuelae, a β-glucosidase involved in macrolide activation. Protein Sci. 2013;22(7):883-92. DOI:10.1002/pro.2204 |
29. Balcewich MD, Stubbs KA, He Y, James TW, Davies GJ, Vocadlo DJ, and Mark BL. (2009). Insight into a strategy for attenuating AmpC-mediated beta-lactam resistance: structural basis for selective inhibition of the glycoside hydrolase NagZ. Protein Sci. 2009;18(7):1541-51. DOI:10.1002/pro.137 |
30. Yamaguchi T, Blázquez B, Hesek D, Lee M, Llarrull LI, Boggess B, Oliver AG, Fisher JF, and Mobashery S. (2012). Inhibitors for Bacterial Cell-Wall Recycling. ACS Med Chem Lett. 2012;3(3):238-242. DOI:10.1021/ml2002746 |
31. Vötsch W and Templin MF. (2000). Characterization of a beta -N-acetylglucosaminidase of Escherichia coli and elucidation of its role in muropeptide recycling and beta -lactamase induction. J Biol Chem. 2000;275(50):39032-8. DOI:10.1074/jbc.M004797200 |
32. Asgarali A, Stubbs KA, Oliver A, Vocadlo DJ, and Mark BL. (2009). Inactivation of the glycoside hydrolase NagZ attenuates antipseudomonal beta-lactam resistance in Pseudomonas aeruginosa. Antimicrob Agents Chemother. 2009;53(6):2274-82. DOI:10.1128/AAC.01617-08 |
33. Tews I, Perrakis A, Oppenheim A, Dauter Z, Wilson KS, and Vorgias CE. (1996). Bacterial chitobiase structure provides insight into catalytic mechanism and the basis of Tay-Sachs disease. Nat Struct Biol. 1996;3(7):638-48. DOI:10.1038/nsb0796-638 |
34. Mark BL, Vocadlo DJ, Knapp S, Triggs-Raine BL, Withers SG, and James MN. (2001). Crystallographic evidence for substrate-assisted catalysis in a bacterial beta-hexosaminidase. J Biol Chem. 2001;276(13):10330-7. DOI:10.1074/jbc.M011067200 |
35. 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 |
36. Li H, Zhao G, Miyake H, Umekawa H, Kimura T, Ohmiya K, and Sakka K. (2006). Identification of a catalytic residue of Clostridium paraputrificum N-acetyl-beta-D-glucosaminidase Nag3A by site-directed mutagenesis. Biosci Biotechnol Biochem. 2006;70(5):1127-33. DOI:10.1271/bbb.70.1127 |
37. Paal K, Ito M, and Withers SG. (2004). Paenibacillus sp. TS12 glucosylceramidase: kinetic studies of a novel sub-family of family 3 glycosidases and identification of the catalytic residues. Biochem J. 2004;378(Pt 1):141-9. DOI:10.1042/BJ20031028 |