Non-viral sialidases. Sialidases or neuraminidases function to bind and hydrolyze terminal sialic acid residues from various glycoconjugates, they play vital roles in pathogenesis, bacterial nutrition and cellular interactions. They have a six-bladed, beta-propeller fold with the non-viral sialidases containing 2-5 Asp-box motifs (most commonly Ser/Thr-X-Asp-[X]-Gly-X-Thr- Trp/Phe). This CD includes eubacterial and eukaryotic sialidases.

BNR repeat-like domain. This family of proteins contains BNR-like repeats suggesting these proteins may act as sialidases.

Glycosyl hydrolases family 43. The glycosyl hydrolase family 43 contains members that are arabinanases. Arabinanases hydrolyze the alpha-1,5-linked L-arabinofuranoside backbone of plant cell wall arabinans. The structure of arabinanase Arb43A from Cellvibrio japonicus reveals a five-bladed beta-propeller fold. A long V-shaped groove, partially enclosed at one end, forms a single extended substrate-binding surface across the face of the propeller.

Glycosyl hydrolase family 43, such as Bacteroides ovatus alpha-L-arabinofuranosidase (BoGH43, XynB). This glycosyl hydrolase family 43 (GH43) subgroup includes enzymes that have been characterized to have alpha-L-arabinofuranosidase (EC 3.2.1.55) and beta-1,4-xylosidase (beta-D-xylosidase;xylan 1,4-beta-xylosidase; EC 3.2.1.37) activities. Beta-1,4-xylosidases are part of an array of hemicellulases that are involved in the final breakdown of plant cell-wall whereby they degrade xylan. They hydrolyze beta-1,4 glycosidic bonds between two xylose units in short xylooligosaccharides. These are inverting enzymes (i.e. they invert the stereochemistry of the anomeric carbon atom of the substrate) that have an aspartate as the catalytic general base, a glutamate as the catalytic general acid and another aspartate that is responsible for pKa modulation and orienting the catalytic acid. Also included in this subfamily are Bacteroides ovatus alpha-L-arabinofuranosidases, BoGH43A and BoGH43B, both having a two-domain architecture, consisting of an N-terminal 5-bladed beta-propeller domain harboring the catalytic active site, and a C-terminal beta-sandwich domain. However, despite significant functional overlap between these two enzymes, BoGH43A and BoGH43B share just 41% sequence identity. The latter appears to be significantly less active on the same substrates, suggesting that these paralogs may play subtly different roles during the degradation of xyloglucans from different sources, or may function most optimally at different stages in the catabolism of xyloglucan oligosaccharides (XyGOs), for example before or after hydrolysis of certain side-chain moieties. It also includes Phanerochaete chrysosporium BKM-F-1767 Xyl, a bifunctional xylosidase/arabinofuranosidase. A common structural feature of GH43 enzymes is a 5-bladed beta-propeller domain that contains the catalytic acid and catalytic base. A long V-shaped groove, partially enclosed at one end, forms a single extended substrate-binding surface across the face of the propeller.

ChainA, Exo-alpha-sialidase [Cutibacterium acnes],7LBV_A Chain A, Exo-alpha-sialidase [Cutibacterium acnes]

Sialidase,Large 68kd Form, Complexed With Galactose [Micromonospora viridifaciens],1EUU_A Sialidase Or Neuraminidase, Large 68kd Form [Micromonospora viridifaciens]

Sialidase[Micromonospora viridifaciens],1EUS_A Sialidase Complexed With 2-Deoxy-2,3-Dehydro-N- Acetylneuraminic Acid [Micromonospora viridifaciens]

Contributionof the Active Site Aspartic Acid to Catalysis in the Bacterial Neuraminidase from Micromonospora viridifaciens. [Micromonospora viridifaciens],1W8O_A Contribution of the Active Site Aspartic Acid to Catalysis in the Bacterial Neuraminidase from Micromonospora viridifaciens [Micromonospora viridifaciens]

Mutagenesisof the Nucleophilic Tyrosine in a Bacterial Sialidase to Phenylalanine. [Micromonospora viridifaciens],1WCQ_B Mutagenesis of the Nucleophilic Tyrosine in a Bacterial Sialidase to Phenylalanine. [Micromonospora viridifaciens],1WCQ_C Mutagenesis of the Nucleophilic Tyrosine in a Bacterial Sialidase to Phenylalanine. [Micromonospora viridifaciens]

Sialidase OS=Micromonospora viridifaciens OX=1881 GN=nedA PE=1 SV=1