Endo-alpha-N-acetylgalactosaminidase. Virulence of pathogenic organisms such as the Gram-positive Streptococcus pneumoniae is largely determined by the ability to degrade host glycoproteins and to metabolize the resultant carbohydrates. This family is the enzymatic region, EC:3.2.1.97, of the cell surface proteins that specifically cleave Gal-beta-1,3-GalNAc-alpha-Ser/Thr (T-antigen, galacto-N-biose), the core 1 type O-linked glycan common to mucin glycoproteins. This reaction is exemplified by the S. pneumoniae protein Endo-alpha-N-acetylgalactosaminidase, where Asp764 is the catalytic nucleophile-base and Glu796 the catalytic proton donor.

Endo-a-N-acetylgalactosaminidase and related glcyosyl hydrolases. This family contains the enzymatically active domain of cell surface proteins that specifically cleave Gal-beta-1,3-GalNAc-alpha-Ser/Thr (T-antigen, galacto-N-biose), the core 1 type O-linked glycan common to mucin glycoproteins (EC:3.2.1.97). It has been classified as glycosyl hydrolase family 101 in the Cazy resource. Virulence of pathogenic organisms such as the Gram-positive Streptococcus pneumoniae and other commensal human bacteria is largely determined by their ability to degrade host glycoproteins and to metabolize the resultant carbohydrates.

Galactose mutarotase-like fold domain. This domain is found in endo-alpha-N-acetylgalactosaminidase present in Streptococcus pneumoniae. Endo-alpha-N-acetylgalactosaminidase is a cell surface-anchored glycoside hydrolase involved in the breakdown of mucin type O-linked glycans. The domain, known as domain 2, exhibits strong structural similarlity to the galactose mutarotase-like fold but lacks the active site residues. Domains, found in a number of glycoside hydrolases, structurally similar to domain 2 confer stability to the multidomain architectures.

Galactose-binding domain-like. Proteins containing a galactose-binding domain-like fold can be found in several different protein families, in both eukaryotes and prokaryotes. The common function of these domains is to bind to specific ligands, such as cell-surface-attached carbohydrate substrates for galactose oxidase and sialidase, phospholipids on the outer side of the mammalian cell membrane for coagulation factor Va, membrane-anchored ephrin for the Eph family of receptor tyrosine kinases, and a complex of broken single-stranded DNA and DNA polymerase beta for XRCC1. The structure of the galactose-binding domain-like members consists of a beta-sandwich, in which the strands making up the sheets exhibit a jellyroll fold.

Endo-alpha-N-acetylgalactosaminidase N-terminal. This is the N-terminal domain found in Streptococcus pneumoniae endo-alpha-N-acetylgalactosaminidase (EC:3.2.1.97), a cell surface-anchored glycoside hydrolase from family GH101 involved in the breakdown of mucin type O-linked glycans. This is a twisted beta-sandwich domain composed of two sheets of six and seven antiparallel beta-strands. The domain appears to be missing the extended metal and carbohydrate-binding loops.

EngBFDARPin Fusion 4b B6 [Bifidobacterium longum]

Thestructure of GH101 D764N mutant from Streptococcus pneumoniae TIGR4 in complex with serinyl T-antigen [Streptococcus pneumoniae TIGR4]

Thestructure of GH101 E796Q mutant from Streptococcus pneumoniae TIGR4 in complex with T-antigen [Streptococcus pneumoniae TIGR4],5A5A_A The structure of GH101 E796Q mutant from Streptococcus pneumoniae TIGR4 in complex with PNP-T-antigen [Streptococcus pneumoniae TIGR4]

EngBFDARPin Fusion 4b H14 [Bifidobacterium longum]

Crystalstructure of endo-alpha-N-acetylgalactosaminidase from Bifidobacterium longum (EngBF) [Bifidobacterium longum]

Endo-alpha-N-acetylgalactosaminidase OS=Streptococcus pneumoniae serotype 4 (strain ATCC BAA-334 / TIGR4) OX=170187 GN=SP_0368 PE=1 SV=1

Endo-alpha-N-acetylgalactosaminidase OS=Streptococcus pneumoniae (strain ATCC BAA-255 / R6) OX=171101 GN=spr0328 PE=1 SV=1

Putative endo-alpha-N-acetylgalactosaminidase OS=Renibacterium salmoninarum (strain ATCC 33209 / DSM 20767 / JCM 11484 / NBRC 15589 / NCIMB 2235) OX=288705 GN=RSal33209_1326 PE=3 SV=2

Sialidase OS=Clostridium septicum OX=1504 PE=3 SV=1