DB code: T00064

RLCP classification 3.900.45300.71 : Transfer
CATH domain 2.60.120.200 : Jelly Rolls
2.120.10.10 : Neuraminidase Catalytic domain
2.40.220.10 : Intramolecular trans-sialidase; domain 3
E.C. 4.2.2.15
CSA 1sll
M-CSA 1sll
MACiE

CATH domain Related DB codes (homologues)
2.120.10.10 : Neuraminidase D00173 M00310 T00065 T00208
2.60.120.200 : Jelly Rolls S00148 D00535 D00666 M00185 S00511 T00208

Uniprot Enzyme Name
UniprotKB Protein name Synonyms CAZy Pfam
Q27701 Anhydrosialidase
EC 4.2.2.15
Anhydroneuraminidase
Sialidase L
CBM40 (Carbohydrate-Binding Module Family 40)
GH33 (Glycoside Hydrolase Family 33)
PF02973 (Sialidase)
[Graphical View]

KEGG enzyme name
anhydrosialidase
anhydroneuraminidase
sialglycoconjugate N-acylneuraminylhydrolase (2,7-cyclizing)
sialidase L

UniprotKB: Accession Number Entry name Activity Subunit Subcellular location Cofactor
Q27701 NANL_MACDE Elimination of alpha-sialyl groups in N- acetylneuraminic acid glycosides, releasing 2,7-anhydro-alpha-N- acetylneuraminate. Secreted, extracellular space.

KEGG Pathways
Map code Pathways E.C.

Compound table
Substrates Products Intermediates
KEGG-id C00270 C04521 C00001
E.C.
Compound N-Acetylneuraminate 2,7-Anhydro-alpha-N-acetylneuraminic acid H2O
Type amide group,carbohydrate,carboxyl group amide group,carbohydrate,carboxyl group H2O
ChEBI 17012
15377
PubChem 439197
440369
22247451
962
1sliA01 Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain Unbound Unbound
1sllA01 Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain Unbound Unbound
2sliA01 Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain Unbound Unbound
3sliA01 Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain Unbound Unbound
4sliA01 Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain Unbound Unbound
1sliA02 Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain Unbound Unbound Intermediate-analogue:DAN
1sllA02 Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain Unbound Unbound
2sliA02 Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain Unbound Bound:SKD
3sliA02 Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain Unbound Bound:SKD
4sliA02 Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain Analogue:CNP Unbound
1sliA03 Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain Unbound Unbound
1sllA03 Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain Unbound Unbound
2sliA03 Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain Unbound Unbound
3sliA03 Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain Unbound Unbound
4sliA03 Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain Unbound Unbound

Reference for Active-site residues
resource references E.C.
Swiss-prot;Q27701 & literature [4]

Active-site residues
PDB Catalytic residues Cofactor-binding residues Modified residues Main-chain involved in catalysis Comment
1sliA01 Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain
1sllA01 Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain
2sliA01 Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain
3sliA01 Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain
4sliA01 Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain
1sliA02 Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain ASP 318;GLU 595;TYR 713
1sllA02 Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain ASP 318;GLU 595;TYR 713
2sliA02 Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain ASP 318;GLU 595;TYR 713
3sliA02 Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain ASP 318;GLU 595;TYR 713
4sliA02 Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain ASP 318;GLU 595;TYR 713
1sliA03 Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain
1sllA03 Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain
2sliA03 Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain
3sliA03 Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain
4sliA03 Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain

References for Catalytic Mechanism
References Sections No. of steps in catalysis
[2]
Fig.4, p.526-528
[4]
Fig.5, p.326-329

References
[1]
Resource
Comments
Medline ID
PubMed ID 2254319
Journal J Biol Chem
Year 1990
Volume 265
Pages 21629-33
Authors Li YT, Nakagawa H, Ross SA, Hansson GC, Li SC
Title A novel sialidase which releases 2,7-anhydro-alpha-N-acetylneuraminic acid from sialoglycoconjugates.
Related PDB
Related UniProtKB
[2]
Resource
Comments X-RAY CRYSTALLOGRAPHY (2.0 ANGSTROMS) OF 81-759.
Medline ID
PubMed ID 9562562
Journal Structure
Year 1998
Volume 6
Pages 521-30
Authors Luo Y, Li SC, Chou MY, Li YT, Luo M
Title The crystal structure of an intramolecular trans-sialidase with a NeuAc alpha2-->3Gal specificity.
Related PDB 1sli 1sll
Related UniProtKB Q27701
[3]
Resource
Comments
Medline ID
PubMed ID 10513893
Journal Biosci Rep
Year 1999
Volume 19
Pages 163-8
Authors Sonnino S, Brocca P, Acquotti D, Bernardi A, Raimondi L, Kiso M, Ishida H, Li SC, Li YT
Title The structural basis for the susceptibility of gangliosides to enzymatic degradation.
Related PDB
Related UniProtKB
[4]
Resource
Comments X-RAY CRYSTALLOGRAPHY (1.8 ANGSTROMS) OF 81-759.
Medline ID
PubMed ID 9878409
Journal J Mol Biol
Year 1999
Volume 285
Pages 323-32
Authors Luo Y, Li SC, Li YT, Luo M
Title The 1.8 A structures of leech intramolecular trans-sialidase complexes: evidence of its enzymatic mechanism.
Related PDB 2sli 3sli 4sli
Related UniProtKB Q27701

Comments
According to the literature [2] & [4], this enzyme catalyzes intramolecular transfer of glycosyl group. The reaction proceeds by SN1 mechanism, as follows:
(1) Tyr713 acts as a modulator, polarizing the C2-O2 bond.
(2) Asp318 may act as a general acid to protonate the leaving O2 atom (probably through a water).
(3) The departure of the leaving group leads to the oxocarbonium intermediate with a positive charge formed on C2 atom, which is stabilized by Asp318 and Glu595.
(4) Asp318 acts as a general base, to activate the incoming hydroxyl O7 atom of grycerol group.
(5) The activated O7 atom makes a nucleophilic attack on the C2 atom to complete the reaction.

Created Updated
2005-04-18 2009-02-26