DB code: T00065

RLCP classification	1.31.36210.99 : Hydrolysis
CATH domain	2.120.10.10 : Neuraminidase	Catalytic domain
	2.60.40.10 : Immunoglobulin-like
	2.60.120.260 : Jelly Rolls
E.C.	3.2.1.18
CSA	1euu
M-CSA	1euu
MACiE

CATH domain	Related DB codes (homologues)
2.120.10.10 : Neuraminidase	D00173 M00310 T00064 T00208
2.60.120.260 : Jelly Rolls	M00124 T00005 T00066
2.60.40.10 : Immunoglobulin-like	M00131 T00257 T00005 M00113 M00127 M00132 M00323 M00325 M00327 M00329 M00330 M00331 M00332 T00307 D00166 D00500 M00112 M00193 T00063 T00067 T00245

Uniprot Enzyme Name
UniprotKB	Protein name	Synonyms	CAZy	Pfam
Q02834	Sialidase	EC 3.2.1.18 Neuraminidase	CBM32 (Carbohydrate-Binding Module Family 32) GH33 (Glycoside Hydrolase Family 33)	PF00754 (F5_F8_type_C) PF10633 (NPCBM_assoc) [Graphical View]

KEGG enzyme name
exo-alpha-sialidase neuraminidase sialidase alpha-neuraminidase acetylneuraminidase

UniprotKB: Accession Number	Entry name	Activity	Subunit	Subcellular location	Cofactor
Q02834	NANH_MICVI	Hydrolysis of alpha-(2->3)-, alpha-(2->6)-, alpha-(2->8)- glycosidic linkages of terminal sialic acid residues in oligosaccharides, glycoproteins, glycolipids, colominic acid and synthetic substrates.		Secreted.

KEGG Pathways
Map code	Pathways	E.C.
MAP00511	N-Glycan degradation
MAP00600	Sphingolipid metabolism
MAP01032	Glycan structures - degradation

Compound table
	Cofactors	Substrates							Products							Intermediates
KEGG-id	C01330	C04730	C06128	C04884	C04927	C06139	C06140	C00001	C00270	C01290	C02686	C06135	C04911	C06140	C06141
E.C.
Compound	Sodium	GM3	N-Acetylneuraminyl-galactosylceramide	N-Acetyl-D-galactosaminyl-(N-acetylneuraminyl)-D-galactosyl-D-glucosylceramide	N-Acetylneuraminyl-D-galactosyl-N-acetyl-D-galactosaminyl-(N- acetylneuraminyl)-D-galactosyl-D-glucosylceramide	GQ1	GT1b	H2O	N-Acetylneuraminate	beta-D-Galactosyl-1,4-beta-D-glucosylceramide	Galactosylceramide	GA2	D-Galactosyl-N-acetyl-D-galactosaminyl-(N-acetylneuraminyl)-D-galactosyl-D-glucosylceramide	GT1b	GD1b	Oxocarbenium-ion-like transition-state
Type	univalent metal (Na+, K+)	amide group,carbohydrate,carboxyl group,lipid,polysaccharide	amide group,carbohydrate,carboxyl group,lipid,polysaccharide	amide group,carbohydrate,carboxyl group,lipid,polysaccharide	amide group,carbohydrate,carboxyl group,lipid,polysaccharide	amide group,carbohydrate,carboxyl group,lipid,polysaccharide	amide group,carbohydrate,carboxyl group,lipid,polysaccharide	H2O	amide group,carbohydrate,carboxyl group	amide group,carbohydrate,lipid,polysaccharide	amide group,carbohydrate,lipid	amide group,carbohydrate,lipid,polysaccharide	amide group,carbohydrate,carboxyl group,lipid,polysaccharide	amide group,carbohydrate,carboxyl group,lipid,polysaccharide	amide group,carbohydrate,carboxyl group,lipid,polysaccharide
ChEBI	29101 29101							15377 15377	17012 17012
PubChem	923 923							22247451 962 22247451 962	439197 439197

1eurA	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound		Unbound	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound
1eusA	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound		Unbound	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound	Transition-state-analogue:DAN
1eutA01	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound		Unbound	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound
1euuA01	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound		Unbound	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound
1w8nA01	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound		Unbound	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound	Transition-state-analogue:DAN
1w8oA01	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound	Analogue:CIT		Unbound	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound
2berA01	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound		Analogue:SLB	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound
2bq9A01	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound		Unbound	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound
2bq9B01	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound		Unbound	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound
2bq9C01	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound		Unbound	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound
1eutA02	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound		Unbound	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound
1euuA02	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound		Unbound	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound
1w8nA02	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound		Unbound	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound
1w8oA02	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound		Unbound	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound
2berA02	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound		Unbound	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound
2bq9A02	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound		Unbound	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound
2bq9B02	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound		Unbound	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound
2bq9C02	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound		Unbound	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound
1eutA03	Bound:_NA	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound		Unbound	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound
1euuA03	Bound:_NA	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound		Unbound	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound
1w8nA03	Bound:_NA	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound		Unbound	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound
1w8oA03	Bound:_NA	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound		Unbound	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound
2berA03	Bound:_NA	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound		Unbound	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound
2bq9A03	Bound:_NA	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound		Unbound	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound
2bq9B03	Bound:_NA	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound		Unbound	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound
2bq9C03	Bound:_NA	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound		Unbound	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound	Unbound

Reference for Active-site residues
resource	references	E.C.
Swiss-prot;Q02834 & literature [3], [7], [8]

Active-site residues
PDB	Catalytic residues	Cofactor-binding residues	Modified residues	Main-chain involved in catalysis	Comment

1eurA	ASP 92;GLU 260;TYR 370
1eusA	ASP 92;GLU 260;TYR 370
1eutA01	ASP 92;GLU 260;TYR 370
1euuA01	ASP 92;GLU 260;TYR 370
1w8nA01	;GLU 260;TYR 370				mutant D92G
1w8oA01	;GLU 260;TYR 370				mutant D92G
2berA01	ASP 92;GLU 260;				mutant Y370G
2bq9A01	ASP 92; ;TYR 370				mutant E260A
2bq9B01	ASP 92; ;TYR 370				mutant E260A
2bq9C01	ASP 92; ;TYR 370				mutant E260A
1eutA02
1euuA02
1w8nA02
1w8oA02
2berA02
2bq9A02
2bq9B02
2bq9C02
1eutA03
1euuA03
1w8nA03
1w8oA03
2berA03
2bq9A03
2bq9B03
2bq9C03

References for Catalytic Mechanism
References	Sections	No. of steps in catalysis
[3]	p.1199
[7]	p.12682, Scheme 2, p.12687-12689
[8]

References
[1]
Resource
Comments
Medline ID
PubMed ID	1613796
Journal	J Mol Biol
Year	1992
Volume	225
Pages	1135-6
Authors	Taylor G, Dineley L, Glowka M, Laver G
Title	Crystallization and preliminary crystallographic study of neuraminidase from Micromonospora viridifaciens.
Related PDB
Related UniProtKB
[2]
Resource
Comments
Medline ID
PubMed ID	7981969
Journal	Trends Microbiol
Year	1994
Volume	2
Pages	271-7
Authors	Vimr ER
Title	Microbial sialidases: does bigger always mean better?
Related PDB
Related UniProtKB
[3]
Resource
Comments	X-RAY CRYSTALLOGRAPHY (1.8 ANGSTROMS).
Medline ID	96164436
PubMed ID	8591030
Journal	Structure
Year	1995
Volume	3
Pages	1197-205
Authors	Gaskell A, Crennell S, Taylor G
Title	The three domains of a bacterial sialidase: a beta-propeller, an immunoglobulin module and a galactose-binding jelly-roll.
Related PDB	1eur 1eus 1eut 1euu
Related UniProtKB	Q02834
[4]
Resource
Comments
Medline ID
PubMed ID	8994884
Journal	Curr Opin Struct Biol
Year	1996
Volume	6
Pages	830-7
Authors	Taylor G
Title	Sialidases: structures, biological significance and therapeutic potential.
Related PDB
Related UniProtKB
[5]
Resource
Comments
Medline ID
PubMed ID	9147054
Journal	Glycobiology
Year	1997
Volume	7
Pages	445-51
Authors	Smith LE, Eichinger D
Title	Directed mutagenesis of the Trypanosoma cruzi trans-sialidase enzyme identifies two domains involved in its sialyltransferase activity.
Related PDB
Related UniProtKB
[6]
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
[7]
Resource
Comments
Medline ID
PubMed ID	14580216
Journal	Biochemistry
Year	2003
Volume	42
Pages	12682-90
Authors	Watson JN, Dookhun V, Borgford TJ, Bennet AJ
Title	Mutagenesis of the conserved active-site tyrosine changes a retaining sialidase into an inverting sialidase.
Related PDB
Related UniProtKB
[8]
Resource
Comments	X-ray crystallography
Medline ID
PubMed ID	15527797
Journal	FEBS Lett
Year	2004
Volume	577
Pages	265-9
Authors	Watson JN, Newstead S, Dookhun V, Taylor G, Bennet AJ
Title	Contribution of the active site aspartic acid to catalysis in the bacterial neuraminidase from Micromonospora viridifaciens.
Related PDB	1w8n 1w8o
Related UniProtKB
[9]
Resource
Comments
Medline ID
PubMed ID	15966735
Journal	Biochemistry
Year	2005
Volume	44
Pages	9117-22
Authors	Newstead S, Watson JN, Knoll TL, Bennet AJ, Taylor G
Title	Structure and mechanism of action of an inverting mutant sialidase.
Related PDB	2ber
Related UniProtKB

Comments
This enzyme belongs to the glycosidase family-33. This enzyme is composed of three domains, the N-terminal catalytic domain, Immunoglobulin-like domain, and the C-terminal F5/8 type C domain. Although Sodium is included as a cofactor, it is not involved in catalysis. It maintains the conformation of the C-terminal domain.(see [3]) According to the literature [7], the catalytic reaction proceeds as follows: (1) Asp92 acts as a general acid, to protonate the leaving group, through a water molecule, to give an oxacarbenium ion-like transition state. (SN1-like reaction) (2) Tyr370, whose pKa is probably modulated by Glu260, makes a nucleophilic attack on the C2 atom of the transition-state, to form a siaryl-enzyme intermediate. (3) Asp92 acts as a general base, to activate the water. (4) The activated water makes a nucleophilic attack on the intermediate, to complete the hydrolysis. ### According to the literature [7], sialyl-based ketal must be much more reactive than ordinary O-glycoside bond.

Comments

This enzyme belongs to the glycosidase family-33. This enzyme is composed of three domains, the N-terminal catalytic domain, Immunoglobulin-like domain, and the C-terminal F5/8 type C domain.
Although Sodium is included as a cofactor, it is not involved in catalysis. It maintains the conformation of the C-terminal domain.(see [3])
According to the literature [7], the catalytic reaction proceeds as follows:
(1) Asp92 acts as a general acid, to protonate the leaving group, through a water molecule, to give an oxacarbenium ion-like transition state. (SN1-like reaction)
(2) Tyr370, whose pKa is probably modulated by Glu260, makes a nucleophilic attack on the C2 atom of the transition-state, to form a siaryl-enzyme intermediate.
(3) Asp92 acts as a general base, to activate the water.
(4) The activated water makes a nucleophilic attack on the intermediate, to complete the hydrolysis.
###
According to the literature [7], sialyl-based ketal must be much more reactive than ordinary O-glycoside bond.

Created	Updated
2005-04-15	2009-02-26