PtsI

• Description: Enzyme I, general (non sugar-specific) component of the PTS. Enzyme I transfers the phosphoryl group from phosphoenolpyruvate (PEP) to the phosphoryl carrier protein (HPr)
  
  

Gene name	ptsI
Synonyms
Essential	no
Product	phosphotransferase system (PTS) enzyme I
Function	PTS-dependent sugar transport
Metabolic function and regulation of this protein in SubtiPathways: Central C-metabolism
MW, pI	62,9 kDa, 4.59
Gene length, protein length	1710 bp, 570 amino acids
Immediate neighbours	ptsH, splA
Get the DNA and protein sequences (Barbe et al., 2009)
Genetic context This image was kindly provided by SubtiList

The gene

Basic information

• Locus tag: BSU13910

Database entries

• DBTBS entry: [1]

• SubtiList entry: [2]

The protein

Basic information/ Evolution

• Catalyzed reaction/ biological activity: Phosphoenolpyruvate + protein L-histidine = pyruvate + protein N(pi)-phospho-L-histidine (according to Swiss-Prot) PEP-dependent autophosphorylation on His-189, transfer of the phosphoryl group to HPr (His-15)

• Protein family: PEP-utilizing enzyme family (according to Swiss-Prot) PEP-utilizing enzyme family

• Paralogous protein(s):

Extended information on the protein

• Kinetic information:

• Domains:
  • HPr binding site (N-Terminal Domain)
  • pyruvate binding site (C-Terminal Domain)
  • pyrophosphate/phosphate carrier histidine (central Domain)

• Modification:
  • transient autophosphorylation on His-189
  • in vivo also phosphorylated on Ser-34 or Ser-36 PubMed

• Cofactor(s): Magnesium

• Effectors of protein activity:

• Interactions:

• Localization: cytoplasm (according to Swiss-Prot)

Database entries

• Structure: 2WQD (Enzyme I from Staphylococcus aureus) PubMed

• UniProt: P08838

• KEGG entry: [3]

• E.C. number: 2.7.3.9 2.7.3.9]

Expression and regulation

• Operon:
  • ptsG-ptsH-ptsI PubMed
  • ptsH-ptsI PubMed

• Sigma factor:
  • ptsG: SigA PubMed
  • ptsH: SigA PubMed

• Regulation:
  • expression activated by glucose (2 fold) (GlcT) PubMed
  • the ptsH promoter is constitutive PubMed
  • subject to negative stringent control upon amino acid limitation (due to control of ptsG transcription initiation) PubMed

• Regulatory mechanism:
  • ptsG: transcriptional antitermination via the GlcT-dependent RNA switch PubMed

• Additional information:

Biological materials

• Mutant: available in Stülke lab
  • GP864 (ermC)
  • GP778 (replacement of glcT and the ptsG-ptsH-ptsI operon by a spc cassette)

• Expression vector:
  • pAG3 (His-tag), available in Galinier lab
  • for expression, purification in E. coli (His-tag), in pWH844: pGP813 available in Stülke lab

• lacZ fusion:

• GFP fusion:

• Antibody:

Labs working on this gene/protein

Josef Deutscher, Paris-Grignon, France

Jörg Stülke, University of Göttingen, Germany Homepage