CitZ

• Description: citrate synthase
  
  

Gene name	citZ
Synonyms	citA2
Essential	no
Product	citrate synthase II
Function	TCA cycle
Metabolic function and regulation of this protein in SubtiPathways: Central C-metabolism
MW, pI	41 kDa, 5.451
Gene length, protein length	1116 bp, 372 aa
Immediate neighbours	ytwI, icd
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: BSU29140

Phenotypes of a mutant

glutamate auxotrophy and a defect in sporulation PubMed

Database entries

• DBTBS entry: [1]

• SubtiList entry: [2]

The protein

Basic information/ Evolution

• Catalyzed reaction/ biological activity: Acetyl-CoA + H₂O + oxaloacetate = citrate + CoA (according to Swiss-Prot)

• Protein family: citrate synthase family (according to Swiss-Prot)

• Paralogous protein(s): MmgD, CitA

Extended information on the protein

• Kinetic information: Michaelis-Menten (Random Sequential Reaction Mechanism) PubMed

• Domains:

• Modification: phosphorylation on Ser-284 PubMed

• Cofactor(s):

• Effectors of protein activity:
  • Inhibited by acetyl-CoA, 2-oxoglutarate and NADH PubMed FEBS Letters
  • Inhibited by citrate and CoA (competitively against acetyl-CoA and non-competitively against oxaloacetate) PubMed
  • Inhibited by ATP competitively in B. subtilis strain 168 and HS 1A17 PubMed PubMed
    • In B. subtilis strain HS 2A2, ATP inhibits a non-competitive fashion PubMed
  • Activated by AMP PubMed

• Interactions:

• Localization:

Database entries

• Structure: 2C6X

• Swiss prot entry: P39120

• KEGG entry: [3]

• E.C. number: 2.3.3.1

Expression and regulation

• Operon: citZ-icd-mdh

• Sigma factor: SigA

• Regulation: repressed by glucose (6.7-fold) (CcpA) PubMed, catabolite repression (CcpA), repression by glucose + glutamate (CcpC) PubMed, repression under anaerobic conditions PubMed
  • repressed in the presence of glucose and glutamate (CcpC) PubMed

• Regulatory mechanism: CcpA: transcription repression, CcpA: transcription repression, CcpC: transcription repression PubMed
  • CcpC: transcription repression (molecular inducer: citrate) PubMed

• Additional information:

Biological materials

• Mutant: GP678 (erm), available in Stülke lab

• Expression vector:
  • pGP1120 (N-terminal Strep-tag, for SPINE, purification from B. subtilis, in pGP380) (available in Stülke lab)
• lacZ fusion:

• GFP fusion:

• two-hybrid system: B. pertussis adenylate cyclase-based bacterial two hybrid system (BACTH), available in Stülke lab

• Antibody: available in Linc Sonenshein lab

Labs working on this gene/protein

Linc Sonenshein, Tufts University, Boston, MA, USA Homepage

Jörg Stülke, University of Göttingen, Germany Homepage

References

1. Blencke et al. (2003) Transcriptional profiling of gene expression in response to glucose in Bacillus subtilis: regulation of the central metabolic pathways. Metab Eng. 5: 133-149 PubMed
2. Macek et al. (2007) The serine/ threonine/ tyrosine phosphoproteome of the model bacterium Bacillus subtilis. Mol. Cell. Proteomics 6: 697-707 PubMed
3. Kim HJ, Roux A, Sonenshein AL (2002b) Direct and indirect roles of CcpA in regulation of Bacillus subtilis Krebs cycle genes. Mol Microbiol 45:179-190. PubMed
4. Nakano MM, Zuber P, Sonenshein AL (1998) Anaerobic regulation of Bacillus subtilis Krebs cycle genes. J Bacteriol. 180: 3304-3311. PubMed
5. Jin S, Sonenshein AL (1994) Identification of two distinct Bacillus subtilis citrate synthase genes J Bacteriol. 176: 4669-4679. PubMed
6. Danson MJ et al. (1984) Citric acid cycle enzymes of the archaebacteria: citrate synthase and succinate thiokinase. FEBS Letters. FEBS Letters
7. Author1, Author2 & Author3 (year) Title Journal volume: page-page. PubMed