Phylogenetic analyses suggest multiple changes of substrate specificity within the Glycosyl hydrolase 20 family

Intra, Jari; Pavesi, Giulio; Horner, David S.

doi:10.1186/1471-2148-8-214

Cited by 54 publications

(54 citation statements)

References 99 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…It is known that glycosidases such as ␤-Gal and ␤-D-mannosidase belong to GH2, which includes Escherichia coli ␤-Gal (LacZ). Glycosidases that have the GH20 catalytic domain and can remove ␤1,4-linked N-acetyl-D-hexosamine residues from nonreducing ends of N-acetyl-D-glucosamine or Nacetyl-D-galactosamine residues of oligosaccharides have been previously reported (26,27). In addition, MsgA showed homology to the Big4 domain, which is a bacterial Ig-like domain found in bacterial surface proteins, including ␤-Gal (BgaA) from Streptococcus pneumoniae (28).…”

Section: Methodsmentioning

confidence: 99%

Identification and Characterization of a Novel Secreted Glycosidase with Multiple Glycosidase Activities in Streptococcus intermedius

et al. 2014

View full text Add to dashboard Cite

Section: Methodsmentioning

confidence: 99%

Identification and Characterization of a Novel Secreted Glycosidase with Multiple Glycosidase Activities in Streptococcus intermedius

et al. 2014

View full text Add to dashboard Cite

“…It has been postulated to have specialized physiological functions, including post-translational modification of N-glycans, degradation of glycoconjugates, and egg-sperm recognition (1). The structural basis for these specialized functions is still unclear.…”

mentioning

confidence: 99%

“…␤-N-Acetyl-D-hexosaminidase (EC 3.2.1.52), a member of the family 20 glycosyl hydrolyases (GH20), 4 is an enzyme that participates in the breakdown of glycosidic bonds of glycans, glycoproteins, and glycolipids (1). It has been postulated to have specialized physiological functions, including post-translational modification of N-glycans, degradation of glycoconjugates, and egg-sperm recognition (1).…”

mentioning

confidence: 99%

Structural Determinants of an Insect β-N-Acetyl-d-hexosaminidase Specialized as a Chitinolytic Enzyme

Liu

Zhang

Liu

et al. 2011

Journal of Biological Chemistry

119

View full text Add to dashboard Cite

␤-N-Acetyl-D-hexosaminidase has been postulated to have a specialized function. However, the structural basis of this specialization is not yet established. OfHex1, the enzyme from the Asian corn borer Ostrinia furnacalis (one of the most destructive pests) has previously been reported to function merely in chitin degradation. Here the vital role of OfHex1 during the pupation of O. furnacalis was revealed by RNA interference, and the crystal structures of OfHex1 and OfHex1 complexed with TMG-chitotriomycin were determined at 2.1 Å . The mechanism of selective inhibition by TMG-chitotriomycin was related to the existence of the ؉1 subsite at the active pocket of OfHex1 and a key residue, Trp 490 , at this site. Mutation of Trp 490 to Ala led to a 2,277-fold decrease in sensitivity toward TMG-chitotriomycin as well as an 18-fold decrease in binding affinity for the substrate (GlcNAc) 2 . Although the overall topology of the catalytic domain of OfHex1 shows a high similarity with the human and bacterial enzymes, OfHex1 is distinguished from these enzymes by large conformational changes linked to an "open-close" mechanism at the entrance of the active site, which is characterized by the "lid" residue, Trp 448 . Mutation of Trp 448 to Ala or Phe resulted in a more than 1,000-fold loss in enzyme activity, due mainly to the effect on k cat . The current work has increased our understanding of the structure-function relationship of OfHex1, shedding light on the structural basis that accounts for the specialized function of ␤-N-acetyl-D-hexosaminidase as well as making the development of species-specific pesticides a likely reality.␤-N-Acetyl-D-hexosaminidase (EC 3.2.1.52), a member of the family 20 glycosyl hydrolyases (GH20), 4 is an enzyme that participates in the breakdown of glycosidic bonds of glycans, glycoproteins, and glycolipids (1). It has been postulated to have specialized physiological functions, including post-translational modification of N-glycans, degradation of glycoconjugates, and egg-sperm recognition (1). The structural basis for these specialized functions is still unclear.It is interesting to note that insects have evolved to have more than one ␤-N-acetyl-D-hexosaminidase, as revealed by genomic analysis of various insects, including Coleoptera, Diptera, Hymenoptera, Lepidoptera, Phthiraptera, and Hemiptera. The activities of insect ␤-N-acetyl-D-hexosaminidases are not restricted to chitin degradation but are also associated with post-translational modification of N-glycans, degradation of glycoconjugates, and egg-sperm recognition, suggesting that these enzymes have rather versatile physiological functions in the growth and development of insects (2). Some of these physiological functions may overlap with those of the same enzymes found in higher organisms. Mammal lysosomal ␤-N-acetyl-D-hexosaminidases are mainly responsible for glycoconjugate degradation in lysosome (3). Likewise, ␤-N-acetyl-D-hexosaminidases from the insects Bombyx mori (4) and Spodoptera frugiperda (5) have broad substrate spe...

show abstract

“…It belongs to glycoside hydrolase family 20 (GH20) (7)(8)(9), the members of which catalyze the hydrolysis of the ␤1-linked NAG group from the nonreducing end of various glycoconjugates, such as glycans, glycoproteins, and glycolipids (10). Members of this family, such as N-acetylhexosaminidase (EC 3.2.1.52) and lacto-N-biosidase (EC 3.2.1.140), have activities toward different substrates.…”

mentioning

confidence: 99%

“…Members of this family, such as N-acetylhexosaminidase (EC 3.2.1.52) and lacto-N-biosidase (EC 3.2.1.140), have activities toward different substrates. They have been postulated to have specialized physiological functions, including posttranslational modification of N-glycans, degradation of glycoconjugates, as well as egg-sperm recognition (10). StrH is a 1312-residue protein that contains a tandem repeat of two GH20 domains.…”

mentioning

confidence: 99%

Structural Basis for the Substrate Specificity of a Novel β-N-Acetylhexosaminidase StrH Protein from Streptococcus pneumoniae R6

Jiang

Zhang

et al. 2011

Journal of Biological Chemistry

View full text Add to dashboard Cite

The ␤-N-acetylhexosaminidase (EC 3.2.1.52) from glycoside hydrolase family 20 (GH20) catalyzes the hydrolysis of the ␤-N-acetylglucosamine (NAG) group from the nonreducing end of various glycoconjugates. The putative surface-exposed N-acetylhexosaminidase StrH/Spr0057 from Streptococcus pneumoniae R6 was proved to contribute to the virulence by removal of ␤(1,2)-linked NAG on host defense molecules following the cleavage of sialic acid and galactose by neuraminidase and ␤-galactosidase, respectively. StrH is the only reported GH20 enzyme that contains a tandem repeat of two 53% sequence-identical catalytic domains (designated as GH20-1 and GH20-2, respectively). Here, we present the 2.1 Å crystal structure of the N-terminal domain of StrH (residues Glu-175 to Lys-642) complexed with NAG. It adopts an overall structure similar to other GH20 enzymes: a (␤/␣) 8 TIM barrel with the active site residing at the center of the ␤-barrel convex side. The kinetic investigation using 4-nitrophenyl N-acetyl-␤-D-glucosaminide as the substrate demonstrated that GH20-1 had an enzymatic activity (k cat /K m ) of one-fourth compared with GH20-2. The lower activity of GH20-1 could be attributed to the substitution of active site Cys-469 of GH20-1 to the counterpart Tyr-903 of GH20-2. A complex model of NAG␤(1,2)Man at the active site of GH20-1 combined with activity assays of the corresponding site-directed mutants characterized two key residues Trp-443 and Tyr-482 at subsite ؉1 of GH20-1 (Trp-876 and Tyr-914 of GH20-2) that might determine the ␤(1,2) substrate specificity. Taken together, these findings shed light on the mechanism of catalytic specificity toward the ␤(1,2)-linked ␤-N-acetylglucosides.

show abstract

Phylogenetic analyses suggest multiple changes of substrate specificity within the Glycosyl hydrolase 20 family

Cited by 54 publications

References 99 publications

Identification and Characterization of a Novel Secreted Glycosidase with Multiple Glycosidase Activities in Streptococcus intermedius

Identification and Characterization of a Novel Secreted Glycosidase with Multiple Glycosidase Activities in Streptococcus intermedius

Structural Determinants of an Insect β-N-Acetyl-d-hexosaminidase Specialized as a Chitinolytic Enzyme

Structural Basis for the Substrate Specificity of a Novel β-N-Acetylhexosaminidase StrH Protein from Streptococcus pneumoniae R6

Contact Info

Product

Resources

About