CitB

• Description: trigger enzyme: aconitase and RNA binding protein
  
  

Gene name	citB
Synonyms
Essential	no
Product	trigger enzyme: aconitate hydratase (aconitase)
Function	TCA cycle
Gene expression levels in SubtiExpress: citB
Interactions involving this protein in SubtInteract: CitB
Metabolic function and regulation of this protein in SubtiPathways: Central C-metabolism
MW, pI	99 kDa, 4.903
Gene length, protein length	2727 bp, 909 aa
Immediate neighbours	sspO, yneN
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, trigger enzyme, RNA binding regulators

This gene is a member of the following regulons

CcpA regulon, CcpC regulon, CodY regulon, FsrA regulon

The gene

Basic information

• Locus tag: BSU18000

Phenotypes of a mutant

• glutamate auxotrophy and a defect in sporulation PubMed

Database entries

• DBTBS entry: [1]

• SubtiList entry: [2]

Additional information

• A mutation was found in this gene after evolution under relaxed selection for sporulation PubMed

The protein

Basic information/ Evolution

• Catalyzed reaction/ biological activity:
  • Citrate <=> isocitrate
  • Binding to iron responsive elements (IRE RNA) in the absence of the FeS cluster PubMed

• Protein family:

• Paralogous protein(s):

Extended information on the protein

• Kinetic information:

• Domains:

• Modification:

• Cofactor(s): FeS cluster

• Effectors of protein activity:

• Interactions:
  • Mdh-CitB PubMed
  • CitG-CitB PubMed

• Localization:

Database entries

• Structure: 1L5J (E. coli)

• UniProt: P09339

• KEGG entry: [3]

• E.C. number: 4.2.1.3

Additional information

• B. subtilis aconitase is both an enzyme and an RNA binding protein (moonlighting protein) PubMed
• extensive information on the structure and enzymatic properties of CitB can be found at Proteopedia

Expression and regulation

• Operon: citB (according to DBTBS)

• Expression browser: citB PubMed

• Sigma factor: SigA PubMed

• Regulation:
  • repressed during growth in the presence of branched chain amino acids (CodY) PubMed
  • repressed in the presence of glucose and glutamate (CcpC) PubMed
  • expressed upon transition into the stationary phase (AbrB) PubMed, indirect negative regulation by AbrB PubMed
  • repressed by glucose (3.7-fold) (CcpA) PubMed
  • repression by glucose + arginine (CcpC) PubMed
  • less expressed under conditions of extreme iron limitation (FsrA) PubMed
  • part of the iron sparing response (FsrA) PubMed

• Regulatory mechanism:
  • CodY: transcription repression PubMed
  • CcpC: transcription repression (molecular inducer: citrate) PubMed1 PubMed2
  • CcpA: transcription repression PubMed
  • FsrA: translational repression PubMed

• Additional information:

Biological materials

• Mutant:
  • GP683 (erm), available in Jörg Stülke's lab
  • GP1441 (spc), available in Jörg Stülke's lab
  • 1A999 ( citB::spec), PubMed, available at BGSC

• Expression vector:
  • GP1439 (citB-Strep (spc)), purification from B. subtilis, for SPINE, available in Jörg Stülke's lab
  • pGP1810 (for expression, purification in E. coli with N-terminal Strep-tag, in pGP172, available in Jörg Stülke's lab

• lacZ fusion:
  • pGP700 (in pAC5), available in Jörg Stülke's lab

• GFP fusion: GP1434 (spc, based on pGP1870), 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

• FLAG-tag construct:
  • GP1144 (spc, based on pGP1331), available in Jörg Stülke's lab
  • GP1145 (kan), available in Jörg Stülke'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

Karl Volz
The functional duality of iron regulatory protein 1.
Curr Opin Struct Biol: 2008, 18(1);106-11
[PubMed:18261896] [WorldCat.org] [DOI] (P p)

Fabian M Commichau, Jörg Stülke
Trigger enzymes: bifunctional proteins active in metabolism and in controlling gene expression.
Mol Microbiol: 2008, 67(4);692-702
[PubMed:18086213] [WorldCat.org] [DOI] (P p)

Patricia J Kiley, Helmut Beinert
The role of Fe-S proteins in sensing and regulation in bacteria.
Curr Opin Microbiol: 2003, 6(2);181-5
[PubMed:12732309] [WorldCat.org] [DOI] (P p)

R L Switzer
Non-redox roles for iron-sulfur clusters in enzymes.
Biofactors: 1989, 2(2);77-86
[PubMed:2696478] [WorldCat.org] (P p)

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)

Meghna Mittal, Kieran B Pechter, Silvia Picossi, Hyun-Jin Kim, Kathryn O Kerstein, Abraham L Sonenshein
Dual role of CcpC protein in regulation of aconitase gene expression in Listeria monocytogenes and Bacillus subtilis.
Microbiology (Reading): 2013, 159(Pt 1);68-76
[PubMed:23139400] [WorldCat.org] [DOI] (I p)

Gregory T Smaldone, Olga Revelles, Ahmed Gaballa, Uwe Sauer, Haike Antelmann, John D Helmann
A global investigation of the Bacillus subtilis iron-sparing response identifies major changes in metabolism.
J Bacteriol: 2012, 194(10);2594-605
[PubMed:22389480] [WorldCat.org] [DOI] (I p)

Christopher T Brown, Laura K Fishwick, Binna M Chokshi, Marissa A Cuff, Jay M Jackson, Travis Oglesby, Alison T Rioux, Enrique Rodriguez, Gregory S Stupp, Austin H Trupp, James S Woollcombe-Clarke, Tracy N Wright, William J Zaragoza, Jennifer C Drew, Eric W Triplett, Wayne L Nicholson
Whole-genome sequencing and phenotypic analysis of Bacillus subtilis mutants following evolution under conditions of relaxed selection for sporulation.
Appl Environ Microbiol: 2011, 77(19);6867-77
[PubMed:21821766] [WorldCat.org] [DOI] (I p)

Weihua Gao, Sen Dai, Quanli Liu, Haijin Xu, Yanlin Bai, Mingqiang Qiao
Effect of site-directed mutagenesis of citB on the expression and activity of Bacillus subtilis aconitase.
Mikrobiologiia: 2010, 79(6);774-8
[PubMed:21446632] [WorldCat.org] (P p)

Weihua Gao, Sen Dai, Quanli Liu, Haijin Xu, Mingqiang Qiao
CitB mutation increases the alkaline protease productivity in Bacillus subtilis.
J Gen Appl Microbiol: 2010, 56(5);403-7
[PubMed:21099137] [WorldCat.org] [DOI] (P 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)

Alexander G Albrecht, Daili J A Netz, Marcus Miethke, Antonio J Pierik, Olaf Burghaus, Florian Peuckert, Roland Lill, Mohamed A Marahiel
SufU is an essential iron-sulfur cluster scaffold protein in Bacillus subtilis.
J Bacteriol: 2010, 192(6);1643-51
[PubMed:20097860] [WorldCat.org] [DOI] (I p)

Ahmed Gaballa, Haike Antelmann, Claudio Aguilar, Sukhjit K Khakh, Kyung-Bok Song, Gregory T Smaldone, John D Helmann
The Bacillus subtilis iron-sparing response is mediated by a Fur-regulated small RNA and three small, basic proteins.
Proc Natl Acad Sci U S A: 2008, 105(33);11927-32
[PubMed:18697947] [WorldCat.org] [DOI] (I p)

Alisa W Serio, Kieran B Pechter, Abraham L Sonenshein
Bacillus subtilis aconitase is required for efficient late-sporulation gene expression.
J Bacteriol: 2006, 188(17);6396-405
[PubMed:16923907] [WorldCat.org] [DOI] (P p)

Hans-Matti Blencke, Irene Reif, Fabian M Commichau, Christian Detsch, Ingrid Wacker, Holger Ludwig, Jörg Stülke
Regulation of citB expression in Bacillus subtilis: integration of multiple metabolic signals in the citrate pool and by the general nitrogen regulatory system.
Arch Microbiol: 2006, 185(2);136-46
[PubMed:16395550] [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, Sam-In Kim, Manoja Ratnayake-Lecamwasam, Kiyoshi Tachikawa, Abraham L Sonenshein, Mark Strauch
Complex regulation of the Bacillus subtilis aconitase gene.
J Bacteriol: 2003, 185(5);1672-80
[PubMed:12591885] [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)

C Alén, A L Sonenshein
Bacillus subtilis aconitase is an RNA-binding protein.
Proc Natl Acad Sci U S A: 1999, 96(18);10412-7
[PubMed:10468622] [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)

J E Craig, M J Ford, D C Blaydon, A L Sonenshein
A null mutation in the Bacillus subtilis aconitase gene causes a block in Spo0A-phosphate-dependent gene expression.
J Bacteriol: 1997, 179(23);7351-9
[PubMed:9393699] [WorldCat.org] [DOI] (P p)

A Fouet, S F Jin, G Raffel, A L Sonenshein
Multiple regulatory sites in the Bacillus subtilis citB promoter region.
J Bacteriol: 1990, 172(9);5408-15
[PubMed:2118511] [WorldCat.org] [DOI] (P p)

A Fouet, A L Sonenshein
A target for carbon source-dependent negative regulation of the citB promoter of Bacillus subtilis.
J Bacteriol: 1990, 172(2);835-44
[PubMed:2105305] [WorldCat.org] [DOI] (P p)

M S Rosenkrantz, D W Dingman, A L Sonenshein
Bacillus subtilis citB gene is regulated synergistically by glucose and glutamine.
J Bacteriol: 1985, 164(1);155-64
[PubMed:2413006] [WorldCat.org] [DOI] (P p)

S H Fisher, B Magasanik
2-Ketoglutarate and the regulation of aconitase and histidase formation in Bacillus subtilis.
J Bacteriol: 1984, 158(1);379-82
[PubMed:6143742] [WorldCat.org] [DOI] (P p)