citZ [Sun Nov 13 2016 11:06:21 GMT+0100 (CET)]

citrate synthase

Locus: BSU29140

Isoelectric point: 5.00

Molecular weight: 41.00 kDa

Function: TCA cycle

Product: citrate synthase II

Essential: no

E.C.: 2.3.3.1

Synonyms: citA2

Genomic Context

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Categories containing this gene/protein

• Metabolism → Carbon metabolism → Carbon core metabolism → TCA cycle
• Groups of genes → Phosphoproteins → Phosphorylation on a Ser residue

Categories containing this gene/protein

• carbon core metabolism, phosphoproteins

This gene is a member of the following regulons

• CcpA regulon, CcpC regulon

Gene

Coordinates on the chromosome (coding sequence): 2,981,151 -> 2,982,269

Phenotypes of a mutant

• glutamate auxotrophy and a defect in sporulation PubMed

The protein

Catalyzed reaction/ biological activity

• Acetyl-CoA H₂O oxaloacetate = citrate CoA (according to Swiss-Prot) [Pubmed| 8045898]

Protein family

• citrate synthase family (according to Swiss-Prot)

Paralogous protein(s)

• MmgD, CitA

Modification

• phosphorylation on Ser-284 PubMed

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

Structure

• 2C6X
• [PDB|A discussion of citrate synthase structure]

Localization

• cytoplasm (homogeneously distributed throughout the cell) PubMed

Interactions

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

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

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

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
• GP797 (citZ::spec), allows expression of icd and mdh, available in Jörg Stülke's lab
• GP1281 (citZ::erm), allows expression of icd and mdh, available in Jörg Stülke's lab
• GP2331 (citZ-icd-mdh::kan), Cre-recombinase is integrated in sacA,available in Jörg Stülke's lab
• GP2333 (citZ-icd-mdh::lox72), Cre-recombinase is integrated in sacA, available in Jörg Stülke's lab

Expression vector

• pGP1120 (N-terminal Strep-tag, for SPINE, purification from B. subtilis, in pGP380) (available in Jörg Stülke's lab)
• pGP1776 (for expression, purification in E. coli with N-terminal Strep-tag, in pGP172, available in Jörg Stülke's lab)
• pGP1761 (expression with N-terminal His-tag from E. coli, in pWH844), available in Jörg Stülke's lab
• pGP2515 (N-terminal Strep-tag, purification from E. coli, in pGP172), available in Jörg Stülke's lab

Two-hybrid system

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

Antibody

• available in Linc Sonenshein's lab

Labs working on this gene/protein

• Linc Sonenshein, Tufts University, Boston, MA, USA Homepage
• Jörg Stülke, University of Göttingen, Germany
• Homepage

References

Reviews

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Original publications

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