DB code: S00420

RLCP classification 3.105.250000.90 : Transfer
CATH domain 3.40.930.10 : Mannitol-specific EII; Chain A Catalytic domain
E.C. 2.7.1.-

CATH domain Related DB codes (homologues)
3.40.930.10 : Mannitol-specific EII; Chain A T00258

Uniprot Enzyme Name
UniprotKB Protein name Synonyms RefSeq Pfam
P69829 Nitrogen regulatory protein
EC 2.7.1.-
Enzyme IIA-NTR
Phosphotransferase enzyme IIA component
PTS system EIIA component
NP_417671.1 (Protein)
NC_000913.2 (DNA/RNA sequence)
YP_491389.1 (Protein)
NC_007779.1 (DNA/RNA sequence)
PF00359 (PTS_EIIA_2)
[Graphical View]

KEGG enzyme name

UniprotKB: Accession Number Entry name Activity Subunit Subcellular location Cofactor
P69829 PTSN_ECOLI Cytoplasm.

KEGG Pathways
Map code Pathways E.C.

Compound table
Substrates Products Intermediates
KEGG-id C04261 C02743 C00615 L00031
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
1a6jA Unbound Unbound Unbound Unbound
1a6jB Analogue:SO4 Unbound Unbound Unbound

Reference for Active-site residues
resource references E.C.

Active-site residues
PDB Catalytic residues Cofactor-binding residues Modified residues Main-chain involved in catalysis Comment
1a6jA ARG 57;HIS 73;HIS 120 HIS 73 (phosphorylated)
1a6jB ARG 57;HIS 73;HIS 120 HIS 73 (phosphorylated)

References for Catalytic Mechanism
References Sections No. of steps in catalysis
Fig.7, Fig.8, p.385 2

Medline ID
PubMed ID 1946374
Journal Proc Natl Acad Sci U S A
Year 1991
Volume 88
Pages 9603-7
Authors Sugiyama JE, Mahmoodian S, Jacobson GR
Title Membrane topology analysis of Escherichia coli mannitol permease by using a nested-deletion method to create mtlA-phoA fusions.
Related PDB
Related UniProtKB P00550
Medline ID
PubMed ID 9551558
Journal Structure
Year 1998
Volume 6
Pages 377-88
Authors van Montfort RL, Pijning T, Kalk KH, Hangyi I, Kouwijzer ML, Robillard GT, Dijkstra BW
Title The structure of the Escherichia coli phosphotransferase IIAmannitol reveals a novel fold with two conformations of the active site.
Related PDB 1a3a
Related UniProtKB P00550
Medline ID
PubMed ID 9636714
Journal J Mol Biol
Year 1998
Volume 279
Pages 245-55
Authors Bordo D, van Monfort RL, Pijning T, Kalk KH, Reizer J, Saier MH Jr, Dijkstra BW
Title The three-dimensional structure of the nitrogen regulatory protein IIANtr from Escherichia coli.
Related PDB 1a6j
Related UniProtKB P69829

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 ( This enzyme also had the same E.C. number previously, which was changed to 2.7.1.-.
In the phosphotransferase (PTS) system, a phosphoryl group is transferred from phosphoenolpyruvate (PEP) via the PTS enzymes, EI, HPr, IIA, IIB to the tranported sugar. The enzyme here is IIA subunit of a mannitol transporter (IIA-mannitol).
His73 (PDB;1a6J) is phosphorylated during the phosphotransfer reaction. A phosphoryl transfer between two PTS proteins involves an in-line attack of the phosphorus atom by the acceptor protein. A trigonal bipyramidal transition state is formed with a pentavalent coordination of the phosphorus atom. Productive breakdown of the transition state results in an inversion of the configuration at the phosphorus atom [2]. Although there is no biochemical evidence for the roles of Arg57/His120 (1a3a), Arg57 is ideally positioned to stabilize the transition state in the phosphoryl transfer from HPr to IIA-mannitol. In contrast, whilst His120 is pointed away from the phosphorylation site for HPr, it might also be needed for the phosphoryl transfer to IIB-mannitol.

Created Updated
2002-08-30 2009-02-26