CitZ

• Description: citrate synthase
  
  

Gene name	citZ
Synonyms	citA2
Essential	no
Product	citrate synthase II
Function	TCA cycle
Gene expression levels in SubtiExpress: citZ
Interactions involving this protein in SubtInteract: CitZ
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	icd, ytwI
Sequences	Protein DNA DNA_with_flanks
Genetic context This image was kindly provided by SubtiList
Expression at a glance   PubMed

Categories containing this gene/protein

carbon core metabolism, phosphoproteins

This gene is a member of the following regulons

CcpA regulon, CcpC regulon

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:
  • CitZ-Mdh-Icd (this is the core of the TCA cycle metabolon) PubMed

• Localization:

Database entries

• Structure:
  • 2C6X
  • A discussion of citrate synthase structure
• UniProt: P39120

• KEGG entry: [3]

• E.C. number: 2.3.3.1

Additional information

• extensive information on the structure and enzymatic properties of CitZ can be found at Proteopedia

Expression and regulation

• Operon:
  • citZ-icd-mdh PubMed

• Expression browser: citZ PubMed

• Sigma factor: SigA PubMed

• Regulation:
  • repression by glucose (6.7-fold) (CcpA) PubMed
  • repression by glucose + glutamate (CcpC) PubMed
  • reduced expression at excess citrate concentrations or iron depletion (CitB) PubMed

• Regulatory mechanism:
  • CcpA: transcription repression, CcpC: transcription repression PubMed
  • CcpC: transcription repression (molecular inducer: citrate) PubMed
  • CitB: mRNA destabilization upon citrate accumulation or iron limitation PubMed

• Additional information:
  • The mRNA has a long 5' leader region. This may indicate RNA-based regulation PubMed

Biological materials

• Mutant: GP678 (erm), GP797 (spec) available in Jörg Stülke's lab
  • 1A999 ( citZ::spec), PubMed, available at BGSC
  • GP790 (citz, icd, mdh::kan), available in Jörg Stülke's lab

• Expression vector:
  • pGP1120 (N-terminal Strep-tag, for SPINE, purification from B. subtilis, in pGP380) (available in Stülke lab)
  • pGP1776 (for expression, purification in E. coli with N-terminal Strep-tag, in pGP172, available in Stülke lab)
  • pGP1761 (expression with N-terminal His-tag from E. coli, in pWH844), available in Jörg Stülke's 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

Original publications

Additional publications: PubMed

Kieran B Pechter, Frederik M Meyer, Alisa W Serio, Jörg Stülke, Abraham L Sonenshein
Two roles for aconitase in the regulation of tricarboxylic acid branch gene expression in Bacillus subtilis.
J Bacteriol: 2013, 195(7);1525-37
[PubMed:23354745] [WorldCat.org] [DOI] (I p)

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)

Irnov Irnov, Cynthia M Sharma, Jörg Vogel, Wade C Winkler
Identification of regulatory RNAs in Bacillus subtilis.
Nucleic Acids Res: 2010, 38(19);6637-51
[PubMed:20525796] [WorldCat.org] [DOI] (I p)

Boris Macek, Ivan Mijakovic, Jesper V Olsen, Florian Gnad, Chanchal Kumar, Peter R Jensen, Matthias Mann
The serine/threonine/tyrosine phosphoproteome of the model bacterium Bacillus subtilis.
Mol Cell Proteomics: 2007, 6(4);697-707
[PubMed:17218307] [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)

Hyun-Jin Kim, Agnes Roux, Abraham L Sonenshein
Direct and indirect roles of CcpA in regulation of Bacillus subtilis Krebs cycle genes.
Mol Microbiol: 2002, 45(1);179-90
[PubMed:12100558] [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)

M M Nakano, P Zuber, A L Sonenshein
Anaerobic regulation of Bacillus subtilis Krebs cycle genes.
J Bacteriol: 1998, 180(13);3304-11
[PubMed:9642180] [WorldCat.org] [DOI] (P p)

S Jin, A L Sonenshein
Characterization of the major citrate synthase of Bacillus subtilis.
J Bacteriol: 1996, 178(12);3658-60
[PubMed:8655569] [WorldCat.org] [DOI] (P p)

S Jin, A L Sonenshein
Transcriptional regulation of Bacillus subtilis citrate synthase genes.
J Bacteriol: 1994, 176(15);4680-90
[PubMed:8045899] [WorldCat.org] [DOI] (P p)

S Jin, A L Sonenshein
Identification of two distinct Bacillus subtilis citrate synthase genes.
J Bacteriol: 1994, 176(15);4669-79
[PubMed:8045898] [WorldCat.org] [DOI] (P p)

D E Johnson, R S Hanson
Bacterial citrate synthases: purification, molecular weight and kinetic mechanism.
Biochim Biophys Acta: 1974, 350(2);336-53
[PubMed:4211224] [WorldCat.org] [DOI] (P p)

V R Flechtner, R S Hanson
Coarse and fine control of citrate synthase from Bacillus subtilis.
Biochim Biophys Acta: 1969, 184(2);252-62
[PubMed:4980242] [WorldCat.org] [DOI] (P p)