DB code: S00046

RLCP classification	3.105.250000.90 : Transfer
CATH domain	1.20.58.80 : Methane Monooxygenase Hydroxylase; Chain G, domain 1	Catalytic domain
E.C.	2.7.1.-
CSA	1e2a
M-CSA	1e2a
MACiE

CATH domain	Related DB codes (homologues)

Uniprot Enzyme Name
UniprotKB	Protein name	Synonyms	RefSeq	Pfam
P23532	Lactose-specific phosphotransferase enzyme IIA component	EC 2.7.1.- PTS system lactose-specific EIIA component EIIA-Lac EIII-Lac	YP_004761516.1 (Protein) NC_015862.1 (DNA/RNA sequence)	PF02255 (PTS_IIA) [Graphical View]

KEGG enzyme name

UniprotKB: Accession Number	Entry name	Activity	Subunit	Subcellular location	Cofactor
P23532	PTLA_LACLA	Protein EIIA N(pi)-phospho-L-histidine + protein EIIB = protein EIIA + protein EIIB N(pi)-phospho-L- histidine/cysteine.	Homotrimer.	Cytoplasm.	Binds 1 magnesium ion per trimer.

KEGG Pathways
Map code	Pathways	E.C.

Compound table
	Substrates		Products		Intermediates
KEGG-id	C04261	C02743	C00615	L00031
E.C.
Compound	Protein N(pi)-phospho-L-histidine	Protein cysteine	Protein histidine	Protein S-phosphoryl-cysteine
Type	aromatic ring (with nitrogen atoms),peptide/protein,phosphate group/phosphate ion	peptide/protein,sulfhydryl group	aromatic ring (with nitrogen atoms),peptide/protein	peptide/protein,phosphate group/phosphate ion,sulfide group
ChEBI
PubChem

1e2aA	Unbound	Unbound	Unbound	Unbound
1e2aB	Unbound	Unbound	Unbound	Unbound
1e2aC	Unbound	Unbound	Unbound	Unbound

Reference for Active-site residues
resource	references	E.C.
Swiss-prot;P23532 & Catalytic Site Atlas

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

1e2aA	HIS 54;HIS 78;GLN 80;ASP 81;HIS 82		HIS 78(phosphorylated)
1e2aB	HIS 54;HIS 78;GLN 80;ASP 81;HIS 82		HIS 78(phosphorylated)
1e2aC	HIS 54;HIS 78;GLN 80;ASP 81;HIS 82		HIS 78(phosphorylated)

References for Catalytic Mechanism
References	Sections	No. of steps in catalysis
[1]	p.782

References
[1]
Resource
Comments
Medline ID
PubMed ID	9261069
Journal	Structure
Year	1997
Volume	5
Pages	775-88
Authors	Sliz P, Engelmann R, Hengstenberg W, Pai EF
Title	The structure of enzyme IIAlactose from Lactococcus lactis reveals a new fold and points to possible interactions of a multicomponent system.
Related PDB	1e2a
Related UniProtKB	P23532

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).

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).

Created	Updated
2002-08-01	2009-02-26