DB code: S00164

CATH domain	2.120.10.20 : Neuraminidase	Catalytic domain
E.C.	3.1.3.8
CSA
M-CSA
MACiE

CATH domain	Related DB codes (homologues)

Uniprot Enzyme Name
UniprotKB	Protein name	Synonyms	Pfam
O66037	3-phytase	EC 3.1.3.8 Phytate 3-phosphatase Myo-inositol-hexaphosphate 3-phosphohydrolase	PF02333 (Phytase) [Graphical View]

KEGG enzyme name
3-phytase 1-phytase phytase phytate 1-phosphatase phytate 6-phosphatase

UniprotKB: Accession Number	Entry name	Activity	Subunit	Subcellular location	Cofactor
O66037	PHYT_BACSD	Myo-inositol hexakisphosphate + H(2)O = 1D- myo-inositol 1,2,4,5,6-pentakisphosphate + phosphate.		Secreted.

KEGG Pathways
Map code	Pathways	E.C.
MAP00562	Inositol phosphate metabolism

Compound table
	Cofactors	Substrates		Products		Intermediates
KEGG-id	C00076	C01204	C00001	C04563	C00009
E.C.
Compound	Calcium	myo-Inositol hexakisphosphate	H2O	D-myo-Inositol 1,2,4,5,6-pentakisphosphate	Orthophosphate
Type	divalent metal (Ca2+, Mg2+)	carbohydrate,phosphate group/phosphate ion	H2O	carbohydrate,phosphate group/phosphate ion	phosphate group/phosphate ion
ChEBI	29108 29108	17401 17401	15377 15377	16507 16507	26078 26078
PubChem	271 271		22247451 962 22247451 962		1004 22486802 1004 22486802

1cvmA	Analogue:5x_CD,3x_CA	Unbound		Unbound	Unbound
1pooA	Bound:2x_CA	Unbound		Unbound	Unbound
1qlgA	Analogue:2x_MG,3x_CA	Unbound		Unbound	Unbound
2pooA	Bound:6x_CA	Unbound		Unbound	Unbound

Reference for Active-site residues
resource	references	E.C.
literature [4]

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

1cvmA		TYR 159;GLU 211;GLU 227;ASP 258;GLU 260;GLN 279(two catalytic Ca2+ binding)
1pooA		TYR 159;GLU 211;GLU 227;ASP 258;GLU 260;GLN 279(two catalytic Ca2+ binding)
1qlgA		TYR 159;GLU 211;GLU 227;ASP 258;GLU 260;GLN 279(two catalytic Ca2+ binding)
2pooA		TYR 159;GLU 211;GLU 227;ASP 258;GLU 260;GLN 279(two catalytic Ca2+ binding)

References for Catalytic Mechanism
References	Sections	No. of steps in catalysis
[4]	p.149-151

References
[1]
Resource
Comments	X-RAY CRYSTALLOGRAPHY (2.05 ANGSTROMS).
Medline ID
PubMed ID	10089471
Journal	Acta Crystallogr D Biol Crystallogr
Year	1999
Volume	55
Pages	691-3.
Authors	Ha NC, Kim YO, Oh TK, Oh BH
Title	Preliminary X-ray crystallographic analysis of a novel phytase from a Bacillus amyloliquefaciens strain.
Related PDB	1cvm 2poo
Related UniProtKB	O66037
[2]
Resource
Comments
Medline ID
PubMed ID	10475631
Journal	Br Poult Sci
Year	1999
Volume	40
Pages	348-52.
Authors	Zanini SF, Sazzad MH
Title	Effects of microbial phytase on growth and mineral utilisation in broilers fed on maize soyabean-based diets.
Related PDB
Related UniProtKB
[3]
Resource
Comments
Medline ID
PubMed ID	11271819
Journal	Folia Microbiol (Praha)
Year	2000
Volume	45
Pages	128-32.
Authors	Dvorakova J, Kopecky J, Havlicek V, Kren V
Title	Formation of myo-inositol phosphates by Aspergillus niger 3-phytase.
Related PDB
Related UniProtKB
[4]
Resource
Comments	X-RAY CRYSTALLOGRAPHY (2.1 ANGSTROMS).
Medline ID
PubMed ID	10655618
Journal	Nat Struct Biol
Year	2000
Volume	7
Pages	147-53.
Authors	Ha NC, Oh BC, Shin S, Kim HJ, Oh TK, Kim YO, Choi KY, Oh BH
Title	Crystal structures of a novel, thermostable phytase in partially and fully calcium-loaded states.
Related PDB	1poo 1qlg
Related UniProtKB	O66037
[5]
Resource
Comments
Medline ID
PubMed ID	11164958
Journal	J Biotechnol
Year	2001
Volume	85
Pages	15-24.
Authors	Jermutus L, Tessier M, Pasamontes L, van Loon AP, Lehmann M
Title	Structure-based chimeric enzymes as an alternative to directed enzyme evolution: phytase as a test case.
Related PDB
Related UniProtKB

Comments
According to the literature [4], there are six calcium-binding sites. Out of six binding sites, three low-affinity calcium-binding sites are located at the active site. In particular, two of the three calcium ions bound at the active site seem to be involved in catalysis, as the coordination geometries of the calcium ions, Ca5 and Ca6, are not complete. They might bind the phosphate groups of the substrate, and stabilize the pentacovalent transition state (see [4]).

Comments

According to the literature [4], there are six calcium-binding sites. Out of six binding sites, three low-affinity calcium-binding sites are located at the active site. In particular, two of the three calcium ions bound at the active site seem to be involved in catalysis, as the coordination geometries of the calcium ions, Ca5 and Ca6, are not complete. They might bind the phosphate groups of the substrate, and stabilize the pentacovalent transition state (see [4]).

Created	Updated
2004-03-22	2009-04-15