DB code: S00841

RLCP classification 4.1514.818600.1130 : Addition
8.113.919760.1180 : Isomerization
CATH domain 3.20.20.70 : TIM Barrel Catalytic domain
E.C. 4.4.1.19
CSA
M-CSA
MACiE

CATH domain Related DB codes (homologues)
3.20.20.70 : TIM Barrel S00215 S00217 S00218 S00219 S00532 S00198 S00220 S00745 S00537 S00538 S00539 S00826 S00235 S00239 S00240 S00243 S00244 S00199 S00200 S00201 S00221 S00222 S00847 S00224 S00225 S00226 D00014 D00029 M00141 T00015 T00239 D00664 D00665 D00804 D00863 T00089

Uniprot Enzyme Name
UniprotKB Protein name Synonyms RefSeq Pfam
Q57703 Phosphosulfolactate synthase
EC 4.4.1.19
EC 4.4.1.19) ((2R)-phospho-3-sulfolactate synthase
PSL synthase
NP_247226.1 (Protein)
NC_000909.1 (DNA/RNA sequence)
PF02679 (ComA)
[Graphical View]
O06739 Phosphosulfolactate synthase
EC 4.4.1.19
EC 4.4.1.19) ((2R)-phospho-3-sulfolactate synthase
PSL synthase
NP_388976.1 (Protein)
NC_000964.3 (DNA/RNA sequence)
PF02679 (ComA)
[Graphical View]

KEGG enzyme name
Phosphosulfolactate synthase
(2R)-phospho-3-sulfolactate synthase
(2R)-O-phospho-3-sulfolactate sulfo-lyase

UniprotKB: Accession Number Entry name Activity Subunit Subcellular location Cofactor
Q57703 COMA_METJA (2R)-2-O-phospho-3-sulfolactate = phosphoenolpyruvate + hydrogen sulfite. Homotrimer (Probable). Magnesium.
O06739 COMA_BACSU (2R)-2-O-phospho-3-sulfolactate = phosphoenolpyruvate + hydrogen sulfite.

KEGG Pathways
Map code Pathways E.C.

Compound table
Cofactors Substrates Products Intermediates
KEGG-id C00305 C00074 C11481 C11536
E.C.
Compound Magnesium phosphoenolpyruvate hydrogen sulfite (2R)-2-O-phospho-3-sulfolactate Enolate intermediate
Type divalent metal (Ca2+, Mg2+) carboxyl group,phosphate group/phosphate ion sulfite carboxyl group,phosphate group/phosphate ion,sulfonate group
ChEBI 18420
 18420
 		44897
 44897
 		17137
 17137
 		32896
 32896
PubChem 888
 888
 		1005
 58114173
 59658623
 1005
 58114173
 59658623
 		104748
 104748
 		443249
 443249
1qwgA00 Unbound Unbound Analogue:SO4_300 Unbound Unbound
1u83A00 Unbound Unbound 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
1qwgA00 LYS 137;ARG 170;ARG 244 GLU 103;GLU 133(Magnesium-1);GLU 168;GLU 205(Magnesium-2)
1u83A00 LYS 139;;ARG 246 GLU 106;GLU 135(Magnesium-1);GLU 170;GLU 207(Magnesium-2) invisible 141-146, 171-188

References for Catalytic Mechanism
References Sections No. of steps in catalysis
[2]
[4]
FIG.4, p.45862

References
[1]
Resource
Comments
Medline ID
PubMed ID 10978150
Journal Biochemistry
Year 2000
Volume 39
Pages 10662-76
Authors Thompson TB, Garrett JB, Taylor EA, Meganathan R, Gerlt JA, Rayment I
Title Evolution of enzymatic activity in the enolase superfamily: structure of o-succinylbenzoate synthase from Escherichia coli in complex with Mg2+ and o-succinylbenzoate.
Related PDB 1fhv
Related UniProtKB
[2]
Resource
Comments CHARACTERIZATION, MUTAGENESIS OF LYS-137.
Medline ID
PubMed ID 11830598
Journal J Biol Chem
Year 2002
Volume 277
Pages 13421-9
Authors Graham DE, Xu H, White RH
Title Identification of coenzyme M biosynthetic phosphosulfolactate synthase: a new family of sulfonate-biosynthesizing enzymes.
Related PDB
Related UniProtKB
[3]
Resource
Comments
Medline ID
PubMed ID 12013276
Journal Nat Prod Rep
Year 2002
Volume 19
Pages 133-47
Authors Graham DE, White RH
Title Elucidation of methanogenic coenzyme biosyntheses: from spectroscopy to genomics.
Related PDB
Related UniProtKB
[4]
Resource
Comments X-RAY CRYSTALLOGRAPHY (1.60 ANGSTROMS).
Medline ID
PubMed ID 12952952
Journal J Biol Chem
Year 2003
Volume 278
Pages 45858-63
Authors Wise EL, Graham DE, White RH, Rayment I
Title The structural determination of phosphosulfolactate synthase from Methanococcus jannaschii at 1.7-A resolution: an enolase that is not an enolase.
Related PDB 1qwg
Related UniProtKB Q57703

Comments
According to the literature [4], although this enzyme does not belong to enolase superfamily(CATH 3.20.20.120), it catalyzes a similar reaction to those by the enolase homologues, which involves an enolate intermediate along with magnesium ion.
Although the literature [4] suggested that it is not a member of the enolase superfamily (CATH 3.20.20.120), some metal-binding residues can be superimposed with the corresponding residues of the enolase homologues, mandelate racemase (D00273 in EzCatDB), glucarate dehydratase (D00261) and chloromuconate cycloisomerase (D00283), using Matras program (by T. Kawabata).
According to the literature [2] and [4], this enzyme catalyzes two succsessive reactions, as follows
(A) Addition of sulfite to phosphoenolpyruvate(PEP), forming an enolate intermediate:
(B) Isomerization of the enolate intermediate, producing phosphosulfolactate:
More detailed mechanism might be as follows:
(A) Addition of sulfite to PEP, forming an enolate intermediate:
(A0) PEP must be stablized by two magnesium ions, through carboxylate oxygens of the intermediate.
(A1) Sulfite molecule, whose negative charge must be stabilized by Arg170 and Arg244' (from the adjacent subunit)(of 1qwg), makes a nucleophilic attack at the C3 atom of an unsaturated carboxylic acid, to form an enolate anion intermediate.
(B) Isomerization of the enolate intermediate, producing phosphosulfolactate:
(B0) The carboxyl group of the enolate intermediate must be stablized by two magnesium ions.
(B1) Lys137 (of 1qwg) may act as a general acid to protonate the C2 atom of the enolate intermediate.

Created Updated
2009-12-15 2010-02-08