Endo-beta-N-acetylglucosaminidases are bacterial chitinases that hydrolyze the chitin core of various asparagine (N)-linked glycans and glycoproteins. The endo-beta-N-acetylglucosaminidases have a glycosyl hydrolase family 18 (GH18) catalytic domain. Some members also have an additional C-terminal glycosyl hydrolase family 20 (GH20) domain while others have an N-terminal domain of unknown function (pfam08522). Members of this family include endo-beta-N-acetylglucosaminidase S (EndoS) from Streptococcus pyogenes, EndoF1, EndoF2, EndoF3, and EndoH from Flavobacterium meningosepticum, and EndoE from Enterococcus faecalis. EndoS is a secreted endoglycosidase from Streptococcus pyogenes that specifically hydrolyzes the glycan on human IgG between two core N-acetylglucosamine residues. EndoE is a secreted endoglycosidase, encoded by the ndoE gene in Enterococcus faecalis, that hydrolyzes the glycan on human RNase B.

Domain of unknown function (DUF1735). This domain of unknown function is found in a number of bacterial proteins including acylhydrolases. The structure of this domain has a beta-sandwich fold.

Bacteroidetes-Associated Carbohydrate-binding (putative) Often N-terminal (BACON) domain. The BACON domain is found in diverse domain architectures and accociated with a wide variety of domains, including carbohydrate-active enzymes and proteases. It was named for its suggested function of carbohydrate binding; the latter was inferred from domain architectures, sequence conservation, and phyletic distribution. However, recent experimental data suggest that its primary function in Bacteroides ovatus endo-xyloglucanase BoGH5A is to distance the catalytic module from the cell surface and confer additional mobility to the catalytic domain for attack of the polysaccharide. No evidence for a direct role in carbohydrate binding could be found in that case. The large majority of BACON domains are found in Bacteroidetes.

Bacteroidetes-Associated Carbohydrate-binding (putative) Often N-terminal (BACON) domain. The BACON domain is found in diverse domain architectures and accociated with a wide variety of domains, including carbohydrate-active enzymes and proteases. It was named for its suggested function of carbohydrate binding; the latter was inferred from domain architectures, sequence conservation, and phyletic distribution. However, recent experimental data suggest that its primary function in Bacteroides ovatus endo-xyloglucanase BoGH5A is to distance the catalytic module from the cell surface and confer additional mobility to the catalytic domain for attack of the polysaccharide. No evidence for a direct role in carbohydrate binding could be found in that case. The large majority of BACON domains are found in Bacteroidetes.

Putative binding domain, N-terminal. The BACON (Bacteroidetes-Associated Carbohydrate-binding Often N-terminal) domain is an all-beta domain found in diverse architectures, principally in combination with carbohydrate-active enzymes and proteases. These architectures suggest a carbohydrate-binding function which is also supported by the nature of BACON's few conserved amino-acids. The phyletic distribution of BACON and other data tentatively suggest that it may frequently function to bind mucin. Further work with the characterized structure of a member of glycoside hydrolase family 5 enzyme, Structure 3ZMR, has found no evidence for carbohydrate-binding for this domain.

Crystalstructure of wild type EndoBT-3987 from Bacteroides thetaiotamicron VPI-5482 [Bacteroides thetaiotaomicron VPI-5482],6T8K_A Crystal structure of Bacteroides thetaiotamicron EndoBT-3987 in complex with Man9GlcNAc product in P1 [Bacteroides thetaiotaomicron VPI-5482],6T8K_B Crystal structure of Bacteroides thetaiotamicron EndoBT-3987 in complex with Man9GlcNAc product in P1 [Bacteroides thetaiotaomicron VPI-5482],6T8L_A Crystal structure of Bacteroides thetaiotamicron EndoBT-3987 with Man9GlcNAc product in P212121 [Bacteroides thetaiotaomicron VPI-5482],6TCW_A Crystal structure of Bacteroides thetaiotamicron EndoBT-3987 with Man5GlcNAc product [Bacteroides thetaiotaomicron VPI-5482],7NWF_A Chain A, Endo-beta-N-acetylglucosaminidase F1 [Bacteroides thetaiotaomicron VPI-5482]

Crystalstructure of Bacteroides thetaiotamicron EndoBT-3987 in complex with Man9GlcNAc2Asn substrate [Bacteroides thetaiotaomicron VPI-5482]

Crystalstructure of an endo-beta-N-acetylglucosaminidase (BT_3987) from BACTEROIDES THETAIOTAOMICRON VPI-5482 at 1.55 A resolution [Bacteroides thetaiotaomicron VPI-5482]

CRYSTALSTRUCTURE OF ENDO-BETA-N-ACETYLGLUCOSAMINIDASE F1, AN ALPHA(SLASH)BETA-BARREL ENZYME ADAPTED FOR A COMPLEX SUBSTRATE [Elizabethkingia meningoseptica]

ChainA, ENDO-BETA-N-ACETYLGLUCOSAMINIDASE H, ENDO H [Streptomyces plicatus]

Endo-beta-N-acetylglucosaminidase F1 OS=Elizabethkingia meningoseptica OX=238 GN=endOF1 PE=1 SV=1

Endo-beta-N-acetylglucosaminidase H OS=Streptomyces plicatus OX=1922 PE=1 SV=1

Endo-beta-N-acetylglucosaminidase OS=Flavobacterium sp. (strain SK1022) OX=148444 PE=1 SV=2