PtsG

• Description: trigger enzyme: major glucose permease of the PTS, EIICBA(Glc) and control of GlcT activity
  
  

Gene name	ptsG
Synonyms	ptsX, crr
Essential	no
Product	trigger enzyme: glucose-specific enzyme IICBA component of the PTS
Function	glucose transport and phosphorylation, control of GlcT activity
Metabolic function and regulation of this protein in SubtiPathways: Central C-metabolism, Sugar catabolism
MW, pI	75,3 kDa, 5.40
Gene length, protein length	2097 bp, 699 amino acids
Immediate neighbours	glcT, ptsH
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: BSU13890

Database entries

• DBTBS entry: [1]

• SubtiList entry: [2]

Categories containing this gene/protein

phosphotransferase systems, carbon core metabolism, trigger enzyme, membrane proteins, phosphoproteins

The protein

Basic information/ Evolution

• Catalyzed reaction/ biological activity: transport and phosphorylation of glucose, receives a phosphate from HPr at the IIA domain (His-620), the phosphate group is then transferred to the IIB domain (Cys-461) an finally to the incoming glucose. In the absence of glucose, PtsG phosphorylates and thereby inactivates the transcriptional antiterminator GlcT.

• Protein family: PTS permease, glucose permease (Glc) family PubMed, PTS enzyme II

• Paralogous protein(s):

Extended information on the protein

• Kinetic information:

• Domains:
  • 11x transmembrane domain (16–36, 89–109, 139–159, 180–200, 233–253, 283–303, 313–333, 338–358, 365–385, 388–408)
  • PTS EIIC domain ( 1-424)
  • PTS EIIB domain (439–520)
  • PTS EIIA domain (568–672)

• Modification: transient phosphorylation (HPr-dependent) on His-620, then internal phosphotransfer from His-620 to Cys-461

• Cofactor(s):

• Effectors of protein activity:

• Interactions: HPr-PtsG PubMed, PtsG-GlcT (for phosphorylation of GlcT) PubMed

• Localization: membrane protein PubMed

Database entries

• Structure: 1AX3 (IIA domain), 1GPR (IIA domain), IIA domain NCBI, NMR IIA domain NCBI

• UniProt: P20166

• KEGG entry: [3]

• E.C. number: 2.7.1.69

Expression and regulation

• Operon: ptsG-ptsH-ptsI PubMed

• Sigma factor: SigA PubMed

• Regulation:
  • expression activated by glucose (32 fold) (GlcT) PubMed
  • subject to negative stringent control upon lysine starvation PubMed

• Regulatory mechanism:
  • transcriptional antitermination via the GlcT-dependent RNA switch PubMed
  • stringent response: due to presence of guanine at +1 position of the transcript PubMed

• Additional information:

Biological materials

• Mutants: all available in Stülke lab
  • GP474 (cat)
  • QB5436 (spc)
  • QB5445 (erm)
  • GP778 (replacement of glcT and the ptsG-ptsH-ptsI operon by a spc cassette)
  • GP926 (substitution of glcT and ptsG by a tet cassette)

• Expression vector:
  • pGP123 (domains BA, in pWH844), available in Stülke lab
  • pGP141 (domains BA, mut: H620D, in pWH844), available in Stülke lab
  • pGP428 (EIIB, in pWH844), available in Stülke lab
  • pGP437(EIIA in pGP570, with thrombin cleavage site), available in Stülke lab

• lacZ fusion:
  • pGP34 (pAC5), available in Stülke lab
  • pGP66 (pAC7), available in Stülke lab
  • pGP606 (mutant terminator, pAC6), available in Stülke lab
  • pGP532 (pAC7), available in Stülke lab
  • series of promoter deletions are available in pAC5 and pAC6, available in Stülke lab
  • series of RAT mutants are available in pAC6, available in Stülke lab

• GFP fusion:

• Antibody:

Labs working on this gene/protein

Jörg Stülke, University of Göttingen, Germany Homepage

References

Reviews

Fabian M Commichau, Jörg Stülke
Trigger enzymes: bifunctional proteins active in metabolism and in controlling gene expression.
Mol Microbiol: 2008, 67(4);692-702
[PubMed:18086213] [WorldCat.org] [DOI] (P p)