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	mdh, citZ
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
  • growth and sporulation defects of the mutant could be partially bypassed by deletion of the major citrate synthase gene (citZ) PubMed

Database entries

• DBTBS entry: [1]

• SubtiList entry: [2]

Categories containing this gene/protein

carbon core metabolism, membrane proteins, phosphoproteins

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, in vitro phosphorylated by PrkC on Thr-138, Thr-147, and Thr-396 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:
  • homodimer PubMed
  • CitZ-Mdh-Icd (this is the core of the TCA cycle metabolon) PubMed
  • GltA-Icd PubMed
  • OdhB-Icd PubMed

• Localization: attached to the membrane PubMed

Database entries

• Structure: 1HQS

• UniProt: 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 PubMed
  • icd-mdh PubMed

• Sigma factor:
  • citZ: SigA PubMed
  • icd: SigA PubMed

• Regulation:
  • citZ: catabolite repression (CcpA) PubMed
  • citZ: repression by glucose + glutamate (CcpC) PubMed

• Regulatory mechanism:
  • CcpA: transcription repression, CcpC: transcription repression PubMed
  • 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)
  • for expression, purification in E. coli with N-terminal His-tag, in pWH844: pGP931, 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

References

Frederik M Meyer, Jan Gerwig, Elke Hammer, Christina Herzberg, Fabian M Commichau, Uwe Völker, Jörg Stülke
Physical interactions between tricarboxylic acid cycle enzymes in Bacillus subtilis: evidence for a metabolon.
Metab Eng: 2011, 13(1);18-27
[PubMed:20933603] [WorldCat.org] [DOI] (I p)

Nico Pietack, Dörte Becher, Sebastian R Schmidl, Milton H Saier, Michael Hecker, Fabian M Commichau, Jörg Stülke
In vitro phosphorylation of key metabolic enzymes from Bacillus subtilis: PrkC phosphorylates enzymes from different branches of basic metabolism.
J Mol Microbiol Biotechnol: 2010, 18(3);129-40
[PubMed:20389117] [WorldCat.org] [DOI] (I p)

Hannes Hahne, Susanne Wolff, Michael Hecker, Dörte Becher
From complementarity to comprehensiveness--targeting the membrane proteome of growing Bacillus subtilis by divergent approaches.
Proteomics: 2008, 8(19);4123-36
[PubMed:18763711] [WorldCat.org] [DOI] (I p)

Christine Eymann, Dörte Becher, Jörg Bernhardt, Katrin Gronau, Anja Klutzny, Michael Hecker
Dynamics of protein phosphorylation on Ser/Thr/Tyr in Bacillus subtilis.
Proteomics: 2007, 7(19);3509-26
[PubMed:17726680] [WorldCat.org] [DOI] (P p)

Alain Lévine, Françoise Vannier, Cédric Absalon, Lauriane Kuhn, Peter Jackson, Elaine Scrivener, Valérie Labas, Joëlle Vinh, Patrick Courtney, Jérôme Garin, Simone J Séror
Analysis of the dynamic Bacillus subtilis Ser/Thr/Tyr phosphoproteome implicated in a wide variety of cellular processes.
Proteomics: 2006, 6(7);2157-73
[PubMed:16493705] [WorldCat.org] [DOI] (P p)

Hans-Matti Blencke, Georg Homuth, Holger Ludwig, Ulrike Mäder, Michael Hecker, Jörg Stülke
Transcriptional profiling of gene expression in response to glucose in Bacillus subtilis: regulation of the central metabolic pathways.
Metab Eng: 2003, 5(2);133-49
[PubMed:12850135] [WorldCat.org] [DOI] (P p)

Satinder K Singh, Stephen P Miller, Antony Dean, Leonard J Banaszak, David C LaPorte
Bacillus subtilis isocitrate dehydrogenase. A substrate analogue for Escherichia coli isocitrate dehydrogenase kinase/phosphatase.
J Biol Chem: 2002, 277(9);7567-73
[PubMed:11751849] [WorldCat.org] [DOI] (P p)

S K Singh, K Matsuno, D C LaPorte, L J Banaszak
Crystal structure of Bacillus subtilis isocitrate dehydrogenase at 1.55 A. Insights into the nature of substrate specificity exhibited by Escherichia coli isocitrate dehydrogenase kinase/phosphatase.
J Biol Chem: 2001, 276(28);26154-63
[PubMed:11290745] [WorldCat.org] [DOI] (P p)

C Jourlin-Castelli, N Mani, M M Nakano, A L Sonenshein
CcpC, a novel regulator of the LysR family required for glucose repression of the citB gene in Bacillus subtilis.
J Mol Biol: 2000, 295(4);865-78
[PubMed:10656796] [WorldCat.org] [DOI] (P p)

K Matsuno, T Blais, A W Serio, T Conway, T M Henkin, A L Sonenshein
Metabolic imbalance and sporulation in an isocitrate dehydrogenase mutant of Bacillus subtilis.
J Bacteriol: 1999, 181(11);3382-91
[PubMed:10348849] [WorldCat.org] [DOI] (P p)

S Jin, P A Levin, K Matsuno, A D Grossman, A L Sonenshein
Deletion of the Bacillus subtilis isocitrate dehydrogenase gene causes a block at stage I of sporulation.
J Bacteriol: 1997, 179(15);4725-32
[PubMed:9244258] [WorldCat.org] [DOI] (P p)

R F Ramaley, M O Hudock
Purification and properties of isocitrate dehydrogenase (NADP) from Thermus aquaticus YT-1, Bacillus subtilis-168 and Chlamydomonas reinhardti-Y-2.
Biochim Biophys Acta: 1973, 315(1);22-36
[PubMed:4147570] [WorldCat.org] [DOI] (P p)