EzCatDB: S00198

DB codeS00198
RLCP classification6.10.400000.116
5.121.670200.6100
4.121.143000.6100
6.20.7100.6120
CATH domainDomain 13.20.20.70Catalytic domain
E.C.2.2.1.2
CSA1onr
MACiEM0148

CATH domainRelated DB codes (homologues)
3.20.20.70S00215,S00217,S00218,S00219,S00532,S00220,S00745,S00537,S00538,S00539,S00826,S00841,S00235,S00239,S00240,S00243,S00244,S00199,S00200,S00201,S00221,S00222,S00847,S00224,S00225,S00226,D00014,D00029,M00141,T00015,T00239,D00664,D00665,D00804,D00863,T00089

Enzyme Name
Swiss-protKEGG

P0A870P37837
Protein nameTransaldolase BTransaldolasetransaldolase
dihydroxyacetonetransferase
dihydroxyacetone synthase
formaldehyde transketolase
SynonymsEC 2.2.1.2
EC 2.2.1.2

KEGG pathways
MAP codePathways
MAP00030Pentose phosphate pathway

Swiss-prot:Accession NumberP0A870P37837
Entry nameTALB_ECOLITALDO_HUMAN
ActivitySedoheptulose 7-phosphate + D-glyceraldehyde 3-phosphate = D-erythrose 4-phosphate + D-fructose 6-phosphate.Sedoheptulose 7-phosphate + D-glyceraldehyde 3-phosphate = D-erythrose 4-phosphate + D-fructose 6-phosphate.
SubunitHomodimer.
Subcellular locationCytoplasm (Probable).Cytoplasm (Probable).
Cofactor



SubstratesProductsintermediates
KEGG-idC00085C00279C00118C00281
CompoundD-Fructose 6-phosphateD-Erythrose 4-phosphateD-Glyceraldehyde 3-phosphateSedoheptulose 7-phosphateSchiff-base intermediate
Typecarbohydrate,phosphate group/phosphate ioncarbohydrate,phosphate group/phosphate ioncarbohydrate,phosphate group/phosphate ioncarbohydrate,phosphate group/phosphate ion
1f05AUnboundUnboundUnboundUnboundUnbound
1f05BUnboundUnboundUnboundUnboundUnbound
1i2nAUnboundUnboundUnboundUnboundUnbound
1i2nBUnboundUnboundUnboundUnboundUnbound
1i2oAUnboundUnboundUnboundUnboundUnbound
1i2oBUnboundUnboundUnboundUnboundUnbound
1i2pAUnboundUnboundUnboundUnboundUnbound
1i2pBUnboundUnboundUnboundUnboundUnbound
1i2qAUnboundUnboundUnboundUnboundUnbound
1i2qBUnboundUnboundUnboundUnboundUnbound
1i2rAUnboundUnboundUnboundUnboundUnbound
1i2rBUnboundUnboundUnboundUnboundUnbound
1onrAUnboundUnboundUnboundUnboundUnbound
1onrBUnboundUnboundUnboundUnboundUnbound
1ucwAUnboundUnboundUnboundUnboundIntermediate-analogue:LLY
1ucwBUnboundUnboundUnboundUnboundIntermediate-analogue:LLY

Active-site residues
resource
Swiss-prot;P30148, P37837 & literature [7], [9], [10], [12], [17]
pdbCatalytic residuesModified residuescomment
1f05AASP  27;GLU 106;LYS 142;THR 167


1f05BASP  27;GLU 106;LYS 142;THR 167


1i2nAASP  17;GLU  96;LYS 132;THR 156

mutant N35A
1i2nBASP  17;GLU  96;LYS 132;THR 156

mutant N35A
1i2oAASP  17;       ;LYS 132;THR 156

mutant E96A
1i2oBASP  17;       ;LYS 132;THR 156

mutant E96A
1i2pA       ;GLU  96;LYS 132;THR 156

mutant D17A
1i2pB       ;GLU  96;LYS 132;THR 156

mutant D17A
1i2qAASP  17;GLU  96;LYS 132;       

mutant T156A
1i2qBASP  17;GLU  96;LYS 132;       

mutant T156A
1i2rAASP  17;GLU  96;LYS 132;THR 156

mutant S176A
1i2rBASP  17;GLU  96;LYS 132;THR 156

mutant S176A
1onrAASP  17;GLU  96;LYS 132;THR 156


1onrBASP  17;GLU  96;LYS 132;THR 156


1ucwAASP  17;GLU  96;LLY 132;THR 156
LLY 132(modified with reduced schiff-base intermediate)

1ucwBASP  17;GLU  96;LLY 132;THR 156
LLY 132(modified with reduced schiff-base intermediate)


References for Catalytic Mechanism
ReferencesSectionsNo. of steps in catalysis
[10]Fig.5, p.721
[11]p.305
[12]Fig.5, p.122
[14]p.294-295
[17]Fig.4, p.2412-2414

references
[1]
PubMed ID4799825
JournalBiochemistry
Year1973
Volume12
Pages5217-23
AuthorsKuhn E, Brand K
TitleComputer analysis of the two-substrate reaction catalyzed by yeast and bovine transaldolase
[2]
PubMed ID945040
JournalArch Biochem Biophys
Year1976
Volume173
Pages577-85
AuthorsTsolas O, Horecker BL
TitleHalf-of-the-sites activity of transaldolase
[3]
PubMed ID776982
JournalJ Biol Chem
Year1976
Volume251
Pages4220-3
AuthorsChristen P, Gasser A
TitleOxidation of the carbanion intermediate of transaldolase by hexacyanoferrate (III)
[4]
PubMed ID728110
JournalBiochem J
Year1978
Volume176
Pages257-82
AuthorsWilliams JF, Blackmore PF, Clark MG
TitleNew reaction sequences for the non-oxidative pentose phosphate pathway
[5]
PubMed ID8357848
JournalBiochim Biophys Acta
Year1993
Volume1182
Pages162-78
AuthorsSchrader MC, Eskey CJ, Simplaceanu V, Ho C
TitleA carbon-13 nuclear magnetic resonance investigation of the metabolic fluxes associated with glucose metabolism in human erythrocytes
[6]
PubMed ID8477719
JournalEur J Biochem
Year1993
Volume213
Pages477-85
AuthorsFlanigan I, Collins JG, Arora KK, MacLeod JK, Williams JF
TitleExchange reactions catalyzed by group-transferring enzymes oppose the quantitation and the unravelling of the identify of the pentose pathway
[7]
PubMed ID8109173
JournalYeast
Year1993
Volume9
Pages1241-9
AuthorsMiosga T, Schaaff-Gerstenschlager I, Franken E, Zimmermann FK
TitleLysine144 is essential for the catalytic activity of Saccharomyces cerevisiae transaldolase
[8]
PubMed ID8534086
JournalAppl Environ Microbiol
Year1995
Volume61
Pages4184-90
AuthorsWalfridsson M, Hallborn J, Penttila M, Keranen S, Hahn-Hagerdal B
TitleXylose-metabolizing Saccharomyces cerevisiae strains overexpressing the TKL1 and TAL1 genes encoding the pentose phosphate pathway enzymes transketolase and transaldolase
[9]
PubMed ID8549825
JournalFEBS Lett
Year1996
Volume378
Pages161-5
AuthorsBanki K, Perl A
TitleInhibition of the catalytic activity of human transaldolase by antibodies and site-directed mutagenesis
[10]
CommentsX-RAY CRYSTALLOGRAPHY (1.87 ANGSTROMS).
Medline ID96399717
PubMed ID8805555
JournalStructure
Year1996
Volume4
Pages715-24
AuthorsJia J, Huang W, Schorken U, Sahm H, Sprenger GA, Lindqvist Y, Schneider G
TitleCrystal structure of transaldolase B from Escherichia coli suggests a circular permutation of the alpha/beta barrel within the class I aldolase family
Related PDB1onr
Related Swiss-protP30148
[11]
PubMed ID9343352
JournalAnnu Rev Microbiol
Year1997
Volume51
Pages285-310
AuthorsTakayama S, McGarvey GJ, Wong CH
TitleMicrobial aldolases and transketolases
[12]
CommentsX-RAY CRYSTALLOGRAPHY (2.2 ANGSTROMS).
Medline ID97160483
PubMed ID9007983
JournalProtein Sci
Year1997
Volume6
Pages119-24
AuthorsJia J, Schorken U, Lindqvist Y, Sprenger GA, Schneider G
TitleCrystal structure of the reduced Schiff-base intermediate complex of transaldolase B from Escherichia coli
Related PDB1ucw
Related Swiss-protP30148
[13]
PubMed ID9883893
JournalFEBS Lett
Year1998
Volume441
Pages247-50
AuthorsSchorken U, Jia J, Sahm H, Sprenger GA, Schneider G
TitleDisruption of Escherichia coli transaldolase into catalytically active monomers
[14]
PubMed ID10048322
JournalProtein Sci
Year1999
Volume8
Pages291-7
AuthorsDalby A, Dauter Z, Littlechild JA
TitleCrystal structure of human muscle aldolase complexed with fructose 1,6-bisphosphate
[15]
CommentsX-ray crystallography
PubMed ID10869557
JournalFEBS Lett
Year2000
Volume475
Pages205-8
AuthorsThorell S, Gergely P Jr, Banki K, Perl A, Schneider G
TitleThe three-dimensional structure of human transaldolase
Related PDB1f05
[16]
PubMed ID11705376
JournalBiochemistry
Year2001
Volume40
Pages13868-75
AuthorsChoi KH, Shi J, Hopkins CE, Tolan DR, Allen KN
TitleSnapshots of catalysis
[17]
CommentsX-RAY CRYSTALLOGRAPHY (2.05 ANGSTROMS).
Medline ID21195256
PubMed ID11298760
JournalEur J Biochem
Year2001
Volume268
Pages2408-15
AuthorsSchorken U, Thorell S, Schurmann M, Jia J, Sprenger GA, Schneider G
TitleIdentification of catalytically important residues in the active site of Escherichia coli transaldolase
Related PDB1i2n,1i2o,1i2p,1i2q,1i2r
Related Swiss-protP30148
[18]
PubMed ID11120740
JournalJ Biol Chem
Year2001
Volume276
Pages11055-61
AuthorsSchurmann M, Sprenger GA
TitleFructose-6-phosphate aldolase is a novel class I aldolase from Escherichia coli and is related to a novel group of bacterial transaldolases
[19]
PubMed ID12418227
JournalMethods Enzymol
Year2002
Volume354
Pages197-201
AuthorsSchneider G, Sprenger GA
TitleTransaldolase B: trapping of Schiff base intermediate between dihydroxyacetone and epsilon-amino group of active-site lysine residue by borohydride reduction.

comments
According to the literature [10], [12] & [17], the catalytic reactions of this enzyme proceed as follows:
(A) Exchange of double-bonded atoms; Schiff-base formation:
(A1) Glu96 (PDB;1onr) acts as a general base to abstract a proton from the sidechain of Lys132 through a water, enhancing its nucleophilicity. This water is oriented by Thr156.
(A2) The activated Lys132 makes a nucleophilic attack on C2-carbonyl carbon, to form a carbinolamine intermediate. The negative charge developed on the C2-oxygen of the intermediate is stabilized by interaction with Thr156. (Here, a proton must transfer from the sidechain amine of Lys132 to the C2-carbonyl oxygen, with a probable assistance by the same water. The water may protonate the C2-carbonyl oxygen, and then deprotonate the amine of Lys132.)
(A3) The lone pair of Lys132 makes another attak on C2-carbon, whilst Glu96 acts as a general acid to protonate the leaving hydroxyl group through the same water. This reaction leads to Schiff-base intermeidate formation.
(B) Eliminative double-bond formation;C3-C4 bond cleavage:
(B1) Glu17 acts as a general base to deprotonate C4-hydroxyl group, leading to the C3-C4 bond cleavage (E2-like reaction). This reaction leads to the formation of carbanion at C2 atom, and the release of the first product, G3P.
(B2) The negative charge formed at C2 facilitates the formation of C2=C3 double-bond, or ketamine (or enamine) intermediate.
(C) Additive double-bond deformation; Addition of the second substrate (E4P):
(C1) The C3 atom of the enamine intemediate makes a nucleophilic attack on the carbonyl carbon of the second substrate, E4P.
(C2) Asp17 acts as a general acid to protonate the aldehyde oxygen of E4P, facilitating the nucleophilic attack of the enamine on E4P. This reaction leads to the Schiff base at Lys132 again.
(D) Exchange of double-bonded atoms; Schiff-base deformation:
(D1) A water molecule is activated by a general base, Glu96, through a second water.
(D2) The activated water makes a nucleophilic attack on the Schiff base carbon, to form a carbinolamine intermediate. The negative charge developed on the C2-oxygen of the intermediate is stabilized by interaction with Thr156. (Here, a proton must transfer from the C2-hydroxylg group to the sidechain amine of Lys132, with a probable assistance by the same water. The water may deprotonate the C2-hydroxyl oxygen, and then protonate the amine of Lys132.)
(D3) The lone pair of the C2-oxygen makes a nucleophilic attack on the C2 atom, whilst Glu96 acts as a general acid to protonate the leaving Lys132 amine group through the same water. This reaction leads to release of the product.

createdupdated
2005-03-252009-03-11


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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