EzCatDB: T00064

DB codeT00064
RLCP classification3.900.45300.71
CATH domainDomain 12.60.120.200
Domain 22.120.10.10Catalytic domain
Domain 32.40.220.10
E.C.4.2.2.15
CSA1sll

CATH domainRelated DB codes (homologues)
2.120.10.10D00173,M00310,T00065,T00208
2.60.120.200S00148,D00535,D00666,M00185,S00511,T00208

Enzyme Name
Swiss-protKEGG

Q27701
Protein nameAnhydrosialidaseanhydrosialidase
anhydroneuraminidase
sialglycoconjugate N-acylneuraminylhydrolase (2,7-cyclizing)
sialidase L
SynonymsEC 4.2.2.15
Sialidase L
Anhydroneuraminidase


Swiss-prot:Accession NumberQ27701
Entry nameNANL_MACDE
ActivityElimination of alpha-sialyl groups in N- acetylneuraminic acid glycosides, releasing 2,7-anhydro-alpha-N- acetylneuraminate.
Subunit
Subcellular locationSecreted, extracellular space.
Cofactor


SubstratesProductsintermediates
KEGG-idC00270C04521C00001
CompoundN-Acetylneuraminate2,7-Anhydro-alpha-N-acetylneuraminic acidH2O
Typeamide group,carbohydrate,carboxyl groupamide group,carbohydrate,carboxyl groupH2O
1sliA01UnboundUnbound

1sllA01UnboundUnbound

2sliA01UnboundUnbound

3sliA01UnboundUnbound

4sliA01UnboundUnbound

1sliA02UnboundUnbound
Intermediate-analogue:DAN
1sllA02UnboundUnbound

2sliA02UnboundBound:SKD

3sliA02UnboundBound:SKD

4sliA02Analogue:CNPUnbound

1sliA03UnboundUnbound

1sllA03UnboundUnbound

2sliA03UnboundUnbound

3sliA03UnboundUnbound

4sliA03UnboundUnbound


Active-site residues
resource
Swiss-prot;Q27701 & literature [4]
pdbCatalytic residues
1sliA01
1sllA01
2sliA01
3sliA01
4sliA01
1sliA02ASP 318;GLU 595;TYR 713
1sllA02ASP 318;GLU 595;TYR 713
2sliA02ASP 318;GLU 595;TYR 713
3sliA02ASP 318;GLU 595;TYR 713
4sliA02ASP 318;GLU 595;TYR 713
1sliA03
1sllA03
2sliA03
3sliA03
4sliA03

References for Catalytic Mechanism
ReferencesSectionsNo. of steps in catalysis
[2]Fig.4, p.526-528
[4]Fig.5, p.326-329

references
[1]
PubMed ID2254319
JournalJ Biol Chem
Year1990
Volume265
Pages21629-33
AuthorsLi YT, Nakagawa H, Ross SA, Hansson GC, Li SC
TitleA novel sialidase which releases 2,7-anhydro-alpha-N-acetylneuraminic acid from sialoglycoconjugates.
[2]
CommentsX-RAY CRYSTALLOGRAPHY (2.0 ANGSTROMS) OF 81-759.
PubMed ID9562562
JournalStructure
Year1998
Volume6
Pages521-30
AuthorsLuo Y, Li SC, Chou MY, Li YT, Luo M
TitleThe crystal structure of an intramolecular trans-sialidase with a NeuAc alpha2-->3Gal specificity.
Related PDB1sli,1sll
Related Swiss-protQ27701
[3]
PubMed ID10513893
JournalBiosci Rep
Year1999
Volume19
Pages163-8
AuthorsSonnino S, Brocca P, Acquotti D, Bernardi A, Raimondi L, Kiso M, Ishida H, Li SC, Li YT
TitleThe structural basis for the susceptibility of gangliosides to enzymatic degradation.
[4]
CommentsX-RAY CRYSTALLOGRAPHY (1.8 ANGSTROMS) OF 81-759.
PubMed ID9878409
JournalJ Mol Biol
Year1999
Volume285
Pages323-32
AuthorsLuo Y, Li SC, Li YT, Luo M
TitleThe 1.8 A structures of leech intramolecular trans-sialidase complexes: evidence of its enzymatic mechanism.
Related PDB2sli,3sli,4sli
Related Swiss-protQ27701

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.

createdupdated
2005-04-182009-02-26


Copyright: Nozomi Nagano, JST & CBRC-AIST
Funded by PRESTO/Japan Science and Technology Corporation (JST) (December 2001 - November 2004)
Funded by Grant-in-Aid for Publication of Scientific Research Results/Japan Society for the Promotion of Science (JSPS) (April 2005 - March 2006)
Funded by Grant-in-Aid for Scientific Research (B)/Japan Society for the Promotion of Science (JSPS) (April 2005 - March 2008)
Funded by BIRD/Japan Science and Technology Corporation (JST) (September 2005 - September 2010)
Funded by BIRD/Japan Science and Technology Corporation (JST) (October 2007 - September 2010)
Funded by Grant-in-Aid for Publication of Scientific Research Results/Japan Society for the Promotion of Science (JSPS) (April 2011 - March 2012)

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