EzCatDB: D00265
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DB codeD00265
RLCP classification6.30.100000.5310 : Double-bonded atom exchange
8.211.591500.5520 : Isomerization
5.30.1645000.5521 : Elimination
4.504.771000.5521 : Addition
8.211.591500.5521 : Isomerization
CATH domainDomain 13.40.640.10 : Aspartate Aminotransferase; domain 2Catalytic domain
Domain 23.90.1150.10 : Aspartate Aminotransferase, domain 1
E.C.2.5.1.48
CSA1cs1,1qgn

CATH domainRelated DB codes (homologues)
3.40.640.10 : Aspartate Aminotransferase; domain 2D00085,D00092,D00101,D00102,D00103,D00104,D00107,D00108,D00109,D00255,D00257,D00258,D00269,D00515,M00031,D00279
3.90.1150.10 : Aspartate Aminotransferase, domain 1D00085,D00092,D00101,D00102,D00103,D00104,D00107,D00108,D00109,D00255,D00257,D00258,D00269,D00515,M00031,D00279

Enzyme Name
UniProtKBKEGG

P00935Q9ZPL5
Protein nameCystathionine gamma-synthase
cystathionine gamma-synthase
O-succinyl-L-homoserine succinate-lyase (adding cysteine)
O-succinylhomoserine (thiol)-lyase
homoserine O-transsuccinylase
O-succinylhomoserine synthase
O-succinylhomoserine synthetase
cystathionine synthase
cystathionine synthetase
homoserine transsuccinylase
4-O-succinyl-L-homoserine:L-cysteineS-(3-amino-3-carboxypropyl)transferase
SynonymsCGS
EC 2.5.1.48
O-succinylhomoserine (thiol)-lyase
Cystathionine gamma-synthase
RefSeqNP_418374.1 (Protein)
NC_000913.2 (DNA/RNA sequence)
YP_491512.1 (Protein)
NC_007779.1 (DNA/RNA sequence)

PfamPF01053 (Cys_Met_Meta_PP)
[Graphical view]
PF01053 (Cys_Met_Meta_PP)
[Graphical view]

KEGG pathways
MAP codePathways
MAP00271Methionine metabolism
MAP00272Cysteine metabolism
MAP00450Selenoamino acid metabolism
MAP00920Sulfur metabolism

UniProtKB:Accession NumberP00935Q9ZPL5
Entry nameMETB_ECOLIQ9ZPL5_TOBAC
ActivityO(4)-succinyl-L-homoserine + L-cysteine = L- cystathionine + succinate.
SubunitHomotetramer.
Subcellular locationCytoplasm.
CofactorPyridoxal phosphate.

Compound table: links to PDB-related databases & PoSSuM

CofactorsSubstratesProductsintermediates
KEGG-idC00018C01118C00097C00542C00042
CompoundPyridoxal phosphateO-Succinyl-L-homoserineL-CysteineCystathionineSuccinateQuinonoid intermediate
Typearomatic ring (with nitrogen atoms),phosphate group/phosphate ionamino acids,carbohydrate,carboxyl groupamino acids,sulfhydryl groupamino acids,sulfide groupcarboxyl group
ChEBI18405
16160
17561
35235
17755
15741

PubChem1051
439406
6419722
5862
834
4083111
21952380
1110

              
1cs1A01Bound:LLPUnboundUnboundUnboundUnboundUnbound
1cs1B01Bound:LLPUnboundUnboundUnboundUnboundUnbound
1cs1C01Bound:LLPUnboundUnboundUnboundUnboundUnbound
1cs1D01Bound:LLPUnboundUnboundUnboundAnalogue:DHDUnbound
1qgnA01Bound:PLPUnboundUnboundUnboundUnboundUnbound
1qgnB01Bound:PLPUnboundUnboundUnboundUnboundUnbound
1qgnC01Bound:PLPUnboundUnboundUnboundUnboundUnbound
1qgnD01Bound:PLPUnboundUnboundUnboundUnboundUnbound
1qgnE01Bound:PLPUnboundUnboundUnboundUnboundUnbound
1qgnF01Bound:PLPUnboundUnboundUnboundUnboundUnbound
1qgnG01Bound:PLPUnboundUnboundUnboundUnboundUnbound
1qgnH01Bound:PLPUnboundUnboundUnboundUnboundUnbound
1i41A01Analogue:HENUnboundUnboundUnboundUnboundIntermediate-analogue:HEN
1i41B01Analogue:HENUnboundUnboundUnboundUnboundIntermediate-analogue:HEN
1i41C01Analogue:HENUnboundUnboundUnboundUnboundIntermediate-analogue:HEN
1i41D01Analogue:HENUnboundUnboundUnboundUnboundIntermediate-analogue:HEN
1i41E01Analogue:HENUnboundUnboundUnboundUnboundIntermediate-analogue:HEN
1i41F01Analogue:HENUnboundUnboundUnboundUnboundIntermediate-analogue:HEN
1i41G01Analogue:HENUnboundUnboundUnboundUnboundIntermediate-analogue:HEN
1i41H01Analogue:HENUnboundUnboundUnboundUnboundIntermediate-analogue:HEN
1i41I01Analogue:HENUnboundUnboundUnboundUnboundIntermediate-analogue:HEN
1i41J01Analogue:HENUnboundUnboundUnboundUnboundIntermediate-analogue:HEN
1i41K01Analogue:HENUnboundUnboundUnboundUnboundIntermediate-analogue:HEN
1i41L01Analogue:HENUnboundUnboundUnboundUnboundIntermediate-analogue:HEN
1i43A01Bound:PLPUnboundUnboundUnboundUnboundUnbound
1i43B01Bound:PLPUnboundUnboundUnboundUnboundUnbound
1i43C01Bound:PLPUnboundUnboundUnboundUnboundUnbound
1i43D01Bound:PLPUnboundUnboundUnboundUnboundUnbound
1i43E01Bound:PLPUnboundUnboundUnboundUnboundUnbound
1i43F01Bound:PLPUnboundUnboundUnboundUnboundUnbound
1i43G01Bound:PLPUnboundUnboundUnboundUnboundUnbound
1i43H01Bound:PLPUnboundUnboundUnboundUnboundUnbound
1i43I01Bound:PLPUnboundUnboundUnboundUnboundUnbound
1i43J01Bound:PLPUnboundUnboundUnboundUnboundUnbound
1i43K01Bound:PLPUnboundUnboundUnboundUnboundUnbound
1i43L01Bound:PLPUnboundUnboundUnboundUnboundUnbound
1i48A01Bound:PLPUnboundUnboundUnboundUnboundUnbound
1i48B01Bound:PLPUnboundUnboundUnboundUnboundUnbound
1i48C01Bound:PLPUnboundUnboundUnboundUnboundUnbound
1i48D01Bound:PLPUnboundUnboundUnboundUnboundUnbound
1i48E01Bound:PLPUnboundUnboundUnboundUnboundUnbound
1i48F01Bound:PLPUnboundUnboundUnboundUnboundUnbound
1i48G01Bound:PLPUnboundUnboundUnboundUnboundUnbound
1i48H01Bound:PLPUnboundUnboundUnboundUnboundUnbound
1i48I01Bound:PLPUnboundUnboundUnboundUnboundUnbound
1i48J01Bound:PLPUnboundUnboundUnboundUnboundUnbound
1i48K01Bound:PLPUnboundUnboundUnboundUnboundUnbound
1i48L01Bound:PLPUnboundUnboundUnboundUnboundUnbound
1cs1A02UnboundUnboundUnboundUnboundUnboundUnbound
1cs1B02UnboundUnboundUnboundUnboundUnboundUnbound
1cs1C02UnboundUnboundUnboundUnboundUnboundUnbound
1cs1D02UnboundUnboundUnboundUnboundUnboundUnbound
1qgnA02UnboundUnboundUnboundUnboundUnboundUnbound
1qgnB02UnboundUnboundUnboundUnboundUnboundUnbound
1qgnC02UnboundUnboundUnboundUnboundUnboundUnbound
1qgnD02UnboundUnboundUnboundUnboundUnboundUnbound
1qgnE02UnboundUnboundUnboundUnboundUnboundUnbound
1qgnF02UnboundUnboundUnboundUnboundUnboundUnbound
1qgnG02UnboundUnboundUnboundUnboundUnboundUnbound
1qgnH02UnboundUnboundUnboundUnboundUnboundUnbound
1i41A02UnboundUnboundUnboundUnboundUnboundUnbound
1i41B02UnboundUnboundUnboundUnboundUnboundUnbound
1i41C02UnboundUnboundUnboundUnboundUnboundUnbound
1i41D02UnboundUnboundUnboundUnboundUnboundUnbound
1i41E02UnboundUnboundUnboundUnboundUnboundUnbound
1i41F02UnboundUnboundUnboundUnboundUnboundUnbound
1i41G02UnboundUnboundUnboundUnboundUnboundUnbound
1i41H02UnboundUnboundUnboundUnboundUnboundUnbound
1i41I02UnboundUnboundUnboundUnboundUnboundUnbound
1i41J02UnboundUnboundUnboundUnboundUnboundUnbound
1i41K02UnboundUnboundUnboundUnboundUnboundUnbound
1i41L02UnboundUnboundUnboundUnboundUnboundUnbound
1i43A02UnboundUnboundUnboundUnboundUnboundUnbound
1i43B02UnboundUnboundUnboundUnboundUnboundUnbound
1i43C02UnboundUnboundUnboundUnboundUnboundUnbound
1i43D02UnboundUnboundUnboundUnboundUnboundUnbound
1i43E02UnboundUnboundUnboundUnboundUnboundUnbound
1i43F02UnboundUnboundUnboundUnboundUnboundUnbound
1i43G02UnboundUnboundUnboundUnboundUnboundUnbound
1i43H02UnboundUnboundUnboundUnboundUnboundUnbound
1i43I02UnboundUnboundUnboundUnboundUnboundUnbound
1i43J02UnboundUnboundUnboundUnboundUnboundUnbound
1i43K02UnboundUnboundUnboundUnboundUnboundUnbound
1i43L02UnboundUnboundUnboundUnboundUnboundUnbound
1i48A02UnboundUnboundUnboundUnboundUnboundUnbound
1i48B02UnboundUnboundUnboundUnboundUnboundUnbound
1i48C02UnboundUnboundUnboundUnboundUnboundUnbound
1i48D02UnboundUnboundUnboundUnboundUnboundUnbound
1i48E02UnboundUnboundUnboundUnboundUnboundUnbound
1i48F02UnboundUnboundUnboundUnboundUnboundUnbound
1i48G02UnboundUnboundUnboundUnboundUnboundUnbound
1i48H02UnboundUnboundUnboundUnboundUnboundUnbound
1i48I02UnboundUnboundUnboundUnboundUnboundUnbound
1i48J02UnboundUnboundUnboundUnboundUnboundUnbound
1i48K02UnboundUnboundUnboundUnboundUnboundUnbound
1i48L02UnboundUnboundUnboundUnboundUnboundUnbound

Active-site residues
resource
literature [4], [7], [10]
pdbCatalytic residuesCofactor-binding residuesModified residues
           
1cs1A01TYR  46;ARG  48;TYR 101;ASP 173;LLP 198
 
LLP 198(Modified by PLP)
1cs1B01TYR  46;ARG  48;TYR 101;ASP 173;LLP 198
 
LLP 198(Modified by PLP)
1cs1C01TYR  46;ARG  48;TYR 101;ASP 173;LLP 198
 
LLP 198(Modified by PLP)
1cs1D01TYR  46;ARG  48;TYR 101;ASP 173;LLP 198
 
LLP 198(Modified by PLP)
1qgnA01TYR 108;ARG 110;TYR 163;ASP 236;LYS 261
LYS 261(PLP binding)
 
1qgnB01TYR 108;ARG 110;TYR 163;ASP 236;LYS 261
LYS 261(PLP binding)
 
1qgnC01TYR 108;ARG 110;TYR 163;ASP 236;LYS 261
LYS 261(PLP binding)
 
1qgnD01TYR 108;ARG 110;TYR 163;ASP 236;LYS 261
LYS 261(PLP binding)
 
1qgnE01TYR 108;ARG 110;TYR 163;ASP 236;LYS 261
LYS 261(PLP binding)
 
1qgnF01TYR 108;ARG 110;TYR 163;ASP 236;LYS 261
LYS 261(PLP binding)
 
1qgnG01TYR 108;ARG 110;TYR 163;ASP 236;LYS 261
LYS 261(PLP binding)
 
1qgnH01TYR 108;ARG 110;TYR 163;ASP 236;LYS 261
LYS 261(PLP binding)
 
1i41A01TYR 108;ARG 110;TYR 163;ASP 236;LYS 261
LYS 261(PLP binding)
 
1i41B01TYR 108;ARG 110;TYR 163;ASP 236;LYS 261
LYS 261(PLP binding)
 
1i41C01TYR 108;ARG 110;TYR 163;ASP 236;LYS 261
LYS 261(PLP binding)
 
1i41D01TYR 108;ARG 110;TYR 163;ASP 236;LYS 261
LYS 261(PLP binding)
 
1i41E01TYR 108;ARG 110;TYR 163;ASP 236;LYS 261
LYS 261(PLP binding)
 
1i41F01TYR 108;ARG 110;TYR 163;ASP 236;LYS 261
LYS 261(PLP binding)
 
1i41G01TYR 108;ARG 110;TYR 163;ASP 236;LYS 261
LYS 261(PLP binding)
 
1i41H01TYR 108;ARG 110;TYR 163;ASP 236;LYS 261
LYS 261(PLP binding)
 
1i41I01TYR 108;ARG 110;TYR 163;ASP 236;LYS 261
LYS 261(PLP binding)
 
1i41J01TYR 108;ARG 110;TYR 163;ASP 236;LYS 261
LYS 261(PLP binding)
 
1i41K01TYR 108;ARG 110;TYR 163;ASP 236;LYS 261
LYS 261(PLP binding)
 
1i41L01TYR 108;ARG 110;TYR 163;ASP 236;LYS 261
LYS 261(PLP binding)
 
1i43A01TYR 108;ARG 110;TYR 163;ASP 236;LYS 261
LYS 261(PLP binding)
 
1i43B01TYR 108;ARG 110;TYR 163;ASP 236;LYS 261
LYS 261(PLP binding)
 
1i43C01TYR 108;ARG 110;TYR 163;ASP 236;LYS 261
LYS 261(PLP binding)
 
1i43D01TYR 108;ARG 110;TYR 163;ASP 236;LYS 261
LYS 261(PLP binding)
 
1i43E01TYR 108;ARG 110;TYR 163;ASP 236;LYS 261
LYS 261(PLP binding)
 
1i43F01TYR 108;ARG 110;TYR 163;ASP 236;LYS 261
LYS 261(PLP binding)
 
1i43G01TYR 108;ARG 110;TYR 163;ASP 236;LYS 261
LYS 261(PLP binding)
 
1i43H01TYR 108;ARG 110;TYR 163;ASP 236;LYS 261
LYS 261(PLP binding)
 
1i43I01TYR 108;ARG 110;TYR 163;ASP 236;LYS 261
LYS 261(PLP binding)
 
1i43J01TYR 108;ARG 110;TYR 163;ASP 236;LYS 261
LYS 261(PLP binding)
 
1i43K01TYR 108;ARG 110;TYR 163;ASP 236;LYS 261
LYS 261(PLP binding)
 
1i43L01TYR 108;ARG 110;TYR 163;ASP 236;LYS 261
LYS 261(PLP binding)
 
1i48A01TYR 108;ARG 110;TYR 163;ASP 236;LYS 261
LYS 261(PLP binding)
 
1i48B01TYR 108;ARG 110;TYR 163;ASP 236;LYS 261
LYS 261(PLP binding)
 
1i48C01TYR 108;ARG 110;TYR 163;ASP 236;LYS 261
LYS 261(PLP binding)
 
1i48D01TYR 108;ARG 110;TYR 163;ASP 236;LYS 261
LYS 261(PLP binding)
 
1i48E01TYR 108;ARG 110;TYR 163;ASP 236;LYS 261
LYS 261(PLP binding)
 
1i48F01TYR 108;ARG 110;TYR 163;ASP 236;LYS 261
LYS 261(PLP binding)
 
1i48G01TYR 108;ARG 110;TYR 163;ASP 236;LYS 261
LYS 261(PLP binding)
 
1i48H01TYR 108;ARG 110;TYR 163;ASP 236;LYS 261
LYS 261(PLP binding)
 
1i48I01TYR 108;ARG 110;TYR 163;ASP 236;LYS 261
LYS 261(PLP binding)
 
1i48J01TYR 108;ARG 110;TYR 163;ASP 236;LYS 261
LYS 261(PLP binding)
 
1i48K01TYR 108;ARG 110;TYR 163;ASP 236;LYS 261
LYS 261(PLP binding)
 
1i48L01TYR 108;ARG 110;TYR 163;ASP 236;LYS 261
LYS 261(PLP binding)
 
1cs1A02 
 
 
1cs1B02 
 
 
1cs1C02 
 
 
1cs1D02 
 
 
1qgnA02 
 
 
1qgnB02 
 
 
1qgnC02 
 
 
1qgnD02 
 
 
1qgnE02 
 
 
1qgnF02 
 
 
1qgnG02 
 
 
1qgnH02 
 
 
1i41A02 
 
 
1i41B02 
 
 
1i41C02 
 
 
1i41D02 
 
 
1i41E02 
 
 
1i41F02 
 
 
1i41G02 
 
 
1i41H02 
 
 
1i41I02 
 
 
1i41J02 
 
 
1i41K02 
 
 
1i41L02 
 
 
1i43A02 
 
 
1i43B02 
 
 
1i43C02 
 
 
1i43D02 
 
 
1i43E02 
 
 
1i43F02 
 
 
1i43G02 
 
 
1i43H02 
 
 
1i43I02 
 
 
1i43J02 
 
 
1i43K02 
 
 
1i43L02 
 
 
1i48A02 
 
 
1i48B02 
 
 
1i48C02 
 
 
1i48D02 
 
 
1i48E02 
 
 
1i48F02 
 
 
1i48G02 
 
 
1i48H02 
 
 
1i48I02 
 
 
1i48J02 
 
 
1i48K02 
 
 
1i48L02 
 
 

References for Catalytic Mechanism
ReferencesSectionsNo. of steps in catalysis
[4]Fig.7, p.6834-68399
[7]Fig.7, p.987-990, p.992-9948
[10]p.797

references
[1]
PubMed ID5646044
JournalBiochim Biophys Acta
Year1968
Volume151
Pages664-9
AuthorsGuggenheim S, Flavin M
TitleProton retention in the gamma-elimination reaction catalysed by cystathionine gamma-synthase.
[2]
PubMed ID4205315
JournalJ Biol Chem
Year1974
Volume249
Pages1139-55
AuthorsDatko AH, Giovanelli J, Mudd SH
TitleHomocysteine biosynthesis in green plants. O-Phosphorylhomoserine as the physiological substrate for cystathionine gamma-synthase.
[3]
PubMed ID9323022
JournalFEBS Lett
Year1997
Volume414
Pages492-6
AuthorsWahl MC, Huber R, Prade L, Marinkovic S, Messerschmidt A, Clausen T
TitleCloning, purification, crystallization, and preliminary X-ray diffraction analysis of cystathionine gamma-synthase from E. coli.
[4]
CommentsX-RAY CRYSTALLOGRAPHY (1.5 ANGSTROMS)
Medline ID99059720
PubMed ID9843488
JournalEMBO J
Year1998
Volume17
Pages6827-38
AuthorsClausen T, Huber R, Prade L, Wahl MC, Messerschmidt A
TitleCrystal structure of Escherichia coli cystathionine gamma-synthase at 1.5 A resolution.
Related PDB1cs1
Related UniProtKBP00935
[5]
PubMed ID9914259
JournalCurr Opin Struct Biol
Year1998
Volume8
Pages759-69
AuthorsJansonius JN
TitleStructure, evolution and action of vitamin B6-dependent enzymes.
[6]
PubMed ID10595588
JournalBiol Chem
Year1999
Volume380
Pages1237-42
AuthorsClausen T, Wahl MC, Messerschmidt A, Huber R, Fuhrmann JC, Laber B, Streber W, Steegborn C
TitleCloning, purification and characterisation of cystathionine gamma-synthase from Nicotiana tabacum.
[7]
CommentsX-ray crystallography
PubMed ID10438597
JournalJ Mol Biol
Year1999
Volume290
Pages983-96
AuthorsSteegborn C, Messerschmidt A, Laber B, Streber W, Huber R, Clausen T
TitleThe crystal structure of cystathionine gamma-synthase from Nicotiana tabacum reveals its substrate and reaction specificity.
Related PDB1qgn
[8]
PubMed ID11098400
JournalC R Acad Sci III
Year2000
Volume323
Pages841-51
AuthorsGakiere B, Ravanel S, Droux M, Douce R, Job D
TitleMechanisms to account for maintenance of the soluble methionine pool in transgenic Arabidopsis plants expressing antisense cystathionine gamma-synthase cDNA.
[9]
PubMed ID10673430
JournalStructure Fold Des
Year2000
Volume8
PagesR1-6
AuthorsSchneider G, Kack H, Lindqvist Y
TitleThe manifold of vitamin B6 dependent enzymes.
[10]
PubMed ID11518531
JournalJ Mol Biol
Year2001
Volume311
Pages789-801
AuthorsSteegborn C, Laber B, Messerschmidt A, Huber R, Clausen T
TitleCrystal structures of cystathionine gamma-synthase inhibitor complexes rationalize the increased affinity of a novel inhibitor.
Related PDB1i41,1i43,1i48
[11]
PubMed ID12121993
JournalJ Biol Chem
Year2002
Volume277
Pages36380-6
AuthorsOminato K, Akita H, Suzuki A, Kijima F, Yoshino T, Yoshino M, Chiba Y, Onouchi H, Naito S
TitleIdentification of a short highly conserved amino acid sequence as the functional region required for posttranscriptional autoregulation of the cystathionine gamma-synthase gene in Arabidopsis.

comments
This enzyme was transferred from E.C. 4.2.99.9 to E.C. 2.5.1.48.
This enzyme belongs to the cystathionine beta-lyase subclass of the type-I PLP-dependent enzyme superfamily (Aminotransferase superfamily) (see [5] & [9]).
This enzyme catalyzes the following reactions:
(A) Formation of external aldimine (with amine group of O-succinyl-L-homocysteine),
(B) Isomerization (change in the position of double-bond),
(C) Elimination of carboxyl ester group, forming double-bonded carbon atoms, leading to beta-gamma unsaturated intermediate,
(D) Addition of the second substrate, sulfide, to the double-bonded beta-carbon of the unsaturated intermediate,
(E) Isomerization (change in the position of double-bond),
(F) Formation of internal aldimine, leading to the elimination of the product from PLP.
According to the literature [4], [7] & [10], these reactions proceed as follows:
Here, Tyr108 (of 1qgn) from the adjacent chain modulates the function of Lys261 as base-acid during catalysis. Moreover, Asp236 stabilizes the positively charged pyridine nitrogen of PLP, increasing its electrophilic character (see [4]).
(A) Formation of external aldimine (with amine group of O-succinyl-L-homocysteine):
(A1) Lys261 (of 1qgn) is covalently bound to the PLP cofactor. (Here, Arg110 (from the adjacent chain) and the protonated aldimine of the PLP lower the pKa of the sidechain of Tyr163)
(A2) Tyr163 acts as a general base, which deprotonates the amine group of the first substrate, O-succinyl-L-homocysteine.
(A3) The deprotonated amine group makes a nucleophilic attack on the C4' atom of the PLP, which is bound to Lys261, leading to a tetrahedral intermediate.
(A4) A proton on the amine from the first substrate must be transferred to the leaving nitrogen atom, somehow.
(A5) A lone pair on the amine group makes a nucleophilic attack on the C4' atom of the PLP, leading to the formation of the double-bond and the release of the leaving group.
(B) Isomerization (change in the position of double-bond) [This reaction does not involve quinoid intermediate. see [4]]:
(B1) Lys261 acts as a general base, to deprotonate the alpha-carbon of the first substrate, now covalently bound to the PLP cofactor, forming a carbanionic inermediate.
(B2) Lys261 acts as a general acid, to protonate the C4' atom of the PLP, leading to the formation of PLP-substrate ketimine.
(C) Elimination of carboxyl ester group, forming double-bonded carbon atoms, leading to beta-gamma unsaturated intermediate:
(C1) Lys261 acts as a general base, to deprotonate the beta-carbon (deprotonation site) of the ketimine intermediate, leading to the formation of transition state, alpha-beta unsaturated ketimine.
(C2) Tyr163 acts as a general acid, to protonate the ester bond of the eliminated group, succinate, resulting in the formation of a beta-gamma unsaturated intermediate and the release of succinate.
(D) Addition of the second substrate, sulfide, to the double-bonded beta-carbon of the beta-gamma unsaturated intermediate:
(D1) The sulfur atom of the second substrate, cysteine, makes a nucleophilic attack on the gamma-carbon (sp2) of the intermediate.
(D2) Lys261 acts as a general acid, to protonate the beta-carbon of the intermdiate, resulting in the formation of the PLP product ketimine.
(E) Isomerization (change in the position of double-bond):
(E1) Lys261 acts as a general base, to deprotonate the C4' atom of the PLP, forming a carbanionic intermediate.
(E2) Lys261 acts as a general acid, to protonate the alpha-carbon of the carbanionic intermediate, returning to the external aldimine.
(F) Formation of internal aldimine, leading to the elimination of the product from PLP: Although this final reaction has not been elucidated in the literature, Lys261 acts as a nucleophile to form the internal aldimine.

createdupdated
2004-07-012009-02-26


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 2008)
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)
Funded by Grant-in-Aid for Publication of Scientific Research Results/Japan Society for the Promotion of Science (JSPS) (April 2012 - March 2013)
Supported by the commission for the Development of Artificial Gene Synthesis Technology for Creating Innovative Biomaterial from the Ministry of Economy, Trade and Industry (METI) (October 2012 - )
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