EC Number |
General Information |
Reference |
---|
3.2.1.140 | evolution |
LnbB is a member of the glycoside hydrolase family 20, GH20 |
753153 |
3.2.1.140 | evolution |
LnbX is a non-classified member of the glycoside hydrolase family |
753153 |
3.2.1.140 | evolution |
the enzyme belongs to the glycoside hydrolase family 20, GH20 |
732092 |
3.2.1.140 | evolution |
the enzyme belongs to the glycosyl hydrolase family 20, GH20 |
753245 |
3.2.1.140 | evolution |
the enzyme belongs to the glycosyl hydrolase family 20, GH20. Domain organization of GH20 beta-N-acetylhexosaminidases, overview |
755088 |
3.2.1.140 | evolution |
the LnbX protein is found only in Bifidobacterium bifidum, Bifidobacterium longum, and a few gut microbes, suggesting that the protein has evolved in specialized niches |
-, 732113 |
3.2.1.140 | metabolism |
the enzyme is critical in the lacto-N-biose pathway |
731652 |
3.2.1.140 | metabolism |
the enzyme liberates lacto-N-biose I, i.e. Gal-beta-(1->3)-GlcNAc, the major core structure, from the nonreducing end of human milk oligosaccharides and plays a key role in the metabolic pathway of these compounds |
732092 |
3.2.1.140 | more |
the enzyme reaction proceeds via a substrate-assisted catalytic mechanism. The enzyme consists of three domains, and the C-terminal domain has a unique beta-trefoil-like fold. Compared with other beta-N-acetylhexosaminidases, lacto-N-biosidase has a wide substrate-binding pocket with a -2 subsite specific for beta-1,3-linked Gal, three-dimensional structure and possible conformational pathway for the lacto-N-biosidase reaction, overview. Enzyme structure and active site structure comparisons. The two catalytic residues of GH20, Asp320 (polarizing residue) and Glu321 (acid/base catalytic residue), form hydrogen bonds with the amide nitrogen of the 2-acetamido group and the O1-hydroxyl,respectively. Tyr-419 is a highly conserved residue in GH20 enzymes, and its side-chain hydroxyl group forms a hydrogen bond with the carbonyl oxygen atom of the 2-acetamido group. Asp467 forms bifurcated hydrogen bonds with the O4- and O6-hydroxyl groups of the GlcNAc residue. Catalytic reaction mechanism and conformational changes analysis |
732092 |
3.2.1.140 | more |
the large Bifidobacterium bifidum lacto-N-biosidase and its truncated mutants are used as model proteins to evaluate the minimal functional unit due to its interest and structural complexity. Structure-function analysis of the wild-type in comparison to different truncated enzyme mutants, and comparisons of enzyme structure models, overview. The lacto-N-biosidase requires GH20b and the lectin-like domain at the N- and C-termini of the catalytic GH20 domain to be fully soluble and functional. The lectin domain provides this remote element to the active site. Restoration of activity of the inactive GH20beta-GH20-alpha construct (model A architecture) by a complementation assay with the lectin-like domain |
755088 |