Icd

• Description: isocitrate dehydrogenase
  
  

Gene name	icd
Synonyms	citC
Essential	no
Product	isocitrate dehydrogenase
Function	TCA cycle
Metabolic function and regulation of this protein in SubtiPathways: Central C-metabolism
MW, pI	46 kDa, 4.833
Gene length, protein length	1269 bp, 423 aa
Immediate neighbours	citZ, mdh
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: BSU29130

Phenotypes of a mutant

reduced ability to sporulate PubMed

Database entries

• DBTBS entry: [1]

• SubtiList entry: [2]

The protein

Basic information/ Evolution

• Catalyzed reaction/ biological activity: Isocitrate + NADP⁺ = 2-oxoglutarate + CO₂ + NADPH (according to Swiss-Prot)

• Protein family: isocitrate and isopropylmalate dehydrogenases family (according to Swiss-Prot)

• Paralogous protein(s):

Extended information on the protein

• Kinetic information: Reversible Michaelis-Menten PubMed

• Domains:

• Modification: phosphorylated PubMed, PubMed

• Cofactor(s): Mg2+, Mn2+

• Effectors of protein activity:
  • Inhibited by glyoxylate, oxaloacetate and oxalomalate PubMed
    • Better inhibition when glyoxylate and oxaloacetate is combined, probably due to the non-enzymatic conversion into oxalomalate, which is a strong inhibitor PubMed

• Interactions:

• Localization: attached to the membrane PubMed

Database entries

• Structure: 1HQS

• Swiss prot entry: P39126

• KEGG entry: [3]

• E.C. number: 1.1.1.42

Additional information

This enzyme requires NADP+ exclusively. No activity was seen on the presence on NAD+ PubMed

Expression and regulation

• Operon:
  • citZ-icd-mdh
  • icd-mdh

• Sigma factor: SigA

• Regulation: repressed by glucose (2.2-fold) (CcpA) PubMed, citZ: catabolite repression (CcpA), repression by glucose + glutamate (CcpC)
  • repressed in the presence of glucose and glutamate (CcpC) PubMed

icd: constitutive

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

• Additional information:

Biological materials

• Mutant: GP666 (spc), GP672 (erm), available in Stülke lab

• Expression vector:
  • pGP1121 (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|Linc Sonenshein]], Tufts University, Boston, MA, USA 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. Matsuno K, Blais T, Serio AW, Conway T, Henkin TM, Sonenshein AL (1999) Metabolic imbalance and sporulation in an isocitrate dehydrogenase mutant of Bacillus subtilis. J Bacteriol 181:3382-3391. PubMed
3. Singh SK, Miller SP, Dean A, Banaszak LJ, LaPorte DC (2002) Bacillus subtilis isocitrate dehydrogenase. A substrate analogue for Escherichia coli isocitrate dehydrogenase kinase/ phosphatase. J Biol Chem 277: 7567-7573. PubMed
4. Hahne et al. (2008) From complementarity to comprehensiveness - targeting the membrane proteome of growing Bacillus subtilis by divergent approaches. Proteomics 8: 4123-4136 PubMed
5. Eymann et al. (2007) Dynamics of protein phosphorylation on Ser/Thr/Tyr in Bacillus subtilis. Proteomics 7: 3509-3526. PubMed
6. Levine et al. (2006) Analysis of the dynamic Bacillus subtilis Ser/Thr/Tyr phosphoproteome implicated in a wide variety of cellular processes. Proteomics 6, 2157-2173. PubMed
7. Author1, Author2 & Author3 (year) Title Journal volume: page-page. PubMed