EzCatDB: S00046

DB codeS00046
RLCP classification3.105.250000.90
CATH domainDomain 11.20.58.80Catalytic domain
E.C.2.7.1.-
CSA1e2a


Enzyme Name
Swiss-prot

P23532
Protein nameLactose-specific phosphotransferase enzyme IIA component
SynonymsEC 2.7.1.-
PTS system lactose-specific EIIA component
EIIA-Lac
EIII-Lac


Swiss-prot:Accession NumberP23532
Entry namePTLA_LACLA
ActivityProtein EIIA N(pi)-phospho-L-histidine + protein EIIB = protein EIIA + protein EIIB N(pi)-phospho-L- histidine/cysteine.
SubunitHomotrimer.
Subcellular locationCytoplasm.
CofactorBinds 1 magnesium ion per trimer.


SubstratesProducts
KEGG-idC04261C02743C00615L00031
CompoundProtein N(pi)-phospho-L-histidineProtein cysteineProtein histidineProtein S-phosphoryl-cysteine
Typearomatic ring (with nitrogen atoms),peptide/protein,phosphate group/phosphate ionpeptide/protein,sulfhydryl grouparomatic ring (with nitrogen atoms),peptide/proteinpeptide/protein,phosphate group/phosphate ion,sulfide group
1e2aAUnboundUnboundUnboundUnbound
1e2aBUnboundUnboundUnboundUnbound
1e2aCUnboundUnboundUnboundUnbound

Active-site residues
resource
Swiss-prot;P23532 & Catalytic Site Atlas
pdbCatalytic residuesModified residues
1e2aAHIS 54;HIS 78;GLN 80;ASP 81;HIS 82
HIS 78(phosphorylated)
1e2aBHIS 54;HIS 78;GLN 80;ASP 81;HIS 82
HIS 78(phosphorylated)
1e2aCHIS 54;HIS 78;GLN 80;ASP 81;HIS 82
HIS 78(phosphorylated)

References for Catalytic Mechanism
ReferencesSectionsNo. of steps in catalysis
[1]p.782

references
[1]
PubMed ID9261069
JournalStructure
Year1997
Volume5
Pages775-88
AuthorsSliz P, Engelmann R, Hengstenberg W, Pai EF
TitleThe structure of enzyme IIAlactose from Lactococcus lactis reveals a new fold and points to possible interactions of a multicomponent system.
Related PDB1e2a
Related Swiss-protP23532

comments
This Enzyme is involved in PTS system, to which the other phosphoryl transferases (S00297, D00527, D00525, S00283, S00420 in EzCatDB) also belong. Many of such enzymes have got the same E.C. number (2.7.1.69). This enzyme also had the same E.C. number previously, which was changed to 2.7.1.-.
Moreover, this enzyme seems to transfer the phosphoryl group from His residue of Phosphocarrier protein HPr (Swiss-prot;Q9CJ83) to Cys residue of the PTS system lactose-specific EIIB component (Swiss-prot;P23531), which is homologous to the counterpart enzyme from E. coli (D00525 in EzCatDB).
His78 is the active site, which is phosphorylated by phosphorylcarrier protein, HPr. The NE atom of His78 must be deprotonated at physiolosical pH [1]. And then, this enzyme phosphorylates IIBlactose domain in PTS system (cf. D00525).

createdupdated
2002-08-012009-02-26
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 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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