citB
168
aconitase, trigger enzyme
Locus
BSU_18000
Molecular weight
99.14 kDa
Isoelectric point
4.9
Function
TCA cycle
Product
aconitase, trigger enzyme
Essential
no
E.C.
4.2.1.3
Synonyms
citB
Outlinks
Genomic Context
Categories containing this gene/protein
List of homologs in different organisms, belongs to COG1048 (Galperin et al., 2021)
This gene is a member of the following regulons
SigA regulon, CcpA regulon, CodY regulon, CcpC regulon, CitB regulon
Gene
Coordinates
1,926,680 1,929,409
Phenotypes of a mutant
glutamate auxotrophy and a defect in sporulation PubMed
The protein
Catalyzed reaction/ biological activity
Citrate --> isocitrate (according to UniProt)
3-hydroxybutane-1,2,3-tricarboxylate --> 2-methyl-cis-aconitate + H2O (according to UniProt)
Binding to iron responsive elements (IRE RNA) in the absence of the FeS cluster PubMed
2-methylaconitate --> 2-methyl-isocitrate in the methylcitric acid cycle PubMed
Protein family
aconitase/IPM isomerase family (with LeuC, according to UniProt)
FeS cluster PubMed
Structure
2B3X (PDB) (the human enzyme, 53% identity) PubMed
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
belongs to the 100 most abundant proteins PubMed
Expression and Regulation
Biological materials
Mutant
GP1275 (citB::erm), available in Jörg Stülke's lab
GP1441 (citB::spec), available in Jörg Stülke's lab
Expression vectors
pFM1, expression of CitB with a cleavable His6-tag at the C-terminus in E. coli, based on pBAD30, available in Jörg Stülke's lab PubMed
pGP939, expression in E. coli, based on pBluescript, 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
FLAG-tag construct
GP1145 citB-3xFLAG kan, available in Jörg Stülke's lab
LacZ fusion
pGP700 (cat, based on pAC5]), available in Jörg Stülke's lab
Antibody
available in Linc Sonenshein's lab
GFP fusion
GP1434 (spc, based on pGP1870), 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
Intermolecular Communication in Bacillus subtilis: RNA-RNA, RNA-Protein and Small Protein-Protein Interactions.Frontiers in molecular biosciences. 2020; 7:178. PMID: 32850966
The functional duality of iron regulatory protein 1.
Current opinion in structural biology. 2008 Feb; 18(1):106-11. doi:10.1016/j.sbi.2007.12.010. PMID:18261896
Trigger enzymes: bifunctional proteins active in metabolism and in controlling gene expression.
Molecular microbiology. 2008 Feb; 67(4):692-702. . PMID:18086213
The role of Fe-S proteins in sensing and regulation in bacteria.
Current opinion in microbiology. 2003 Apr; 6(2):181-5. . PMID:12732309
Non-redox roles for iron-sulfur clusters in enzymes.
BioFactors (Oxford, England). 1989 Dec; 2(2):77-86. . PMID:2696478
Original Publications
Developmentally-regulated proteolysis by MdfA and ClpCP mediates metabolic differentiation during Bacillus subtilis sporulation.bioRxiv : the preprint server for biology. 2024 Nov 26; . PMID: 39651166
Protein complexes in cells by AI-assisted structural proteomics.Molecular systems biology. 2023 Feb 23; :e11544. PMID: 36815589
First Biochemical Characterization of a Methylcitric Acid Cycle from Bacillus subtilis strain 168.
Biochemistry. 2017 Sep 28; . doi:10.1021/acs.biochem.7b00778. PMID:28956599
Two roles for aconitase in the regulation of tricarboxylic acid branch gene expression in Bacillus subtilis.
Journal of bacteriology. 2013 Apr; 195(7):1525-37. doi:10.1128/JB.01690-12. PMID:23354745
Dual role of CcpC protein in regulation of aconitase gene expression in Listeria monocytogenes and Bacillus subtilis.
Microbiology (Reading, England). 2013 Jan; 159(Pt 1):68-76. doi:10.1099/mic.0.063388-0. PMID:23139400
A global investigation of the Bacillus subtilis iron-sparing response identifies major changes in metabolism.
Journal of bacteriology. 2012 May; 194(10):2594-605. doi:10.1128/JB.05990-11. PMID:22389480
Whole-genome sequencing and phenotypic analysis of Bacillus subtilis mutants following evolution under conditions of relaxed selection for sporulation.
Applied and environmental microbiology. 2011 Oct; 77(19):6867-77. doi:10.1128/AEM.05272-11. PMID:21821766
The frataxin homologue Fra plays a key role in intracellular iron channeling in Bacillus subtilis.
Chembiochem : a European journal of chemical biology. 2011 Sep 05; 12(13):2052-61. doi:10.1002/cbic.201100190. PMID:21744456
Effect of site-directed mutagenesis of citB on the expression and activity of Bacillus subtilis aconitase.
Mikrobiologiia.; 79(6):774-8. . PMID:21446632
CitB mutation increases the alkaline protease productivity in Bacillus subtilis.
The Journal of general and applied microbiology. 2010 Oct; 56(5):403-7. . PMID:21099137
Physical interactions between tricarboxylic acid cycle enzymes in Bacillus subtilis: evidence for a metabolon.
Metabolic engineering. 2011 Jan; 13(1):18-27. doi:10.1016/j.ymben.2010.10.001. PMID:20933603
Genome-wide binding profiles of the Bacillus subtilis transition state regulator AbrB and its homolog Abh reveals their interactive role in transcriptional regulation.
Nucleic acids research. 2011 Jan; 39(2):414-28. doi:10.1093/nar/gkq780. PMID:20817675
SufU is an essential iron-sulfur cluster scaffold protein in Bacillus subtilis.
Journal of bacteriology. 2010 Mar; 192(6):1643-51. doi:10.1128/JB.01536-09. PMID:20097860
The Bacillus subtilis iron-sparing response is mediated by a Fur-regulated small RNA and three small, basic proteins.
Proceedings of the National Academy of Sciences of the United States of America. 2008 Aug 19; 105(33):11927-32. doi:10.1073/pnas.0711752105. PMID:18697947
Expression of yeast mitochondrial aconitase in Bacillus subtilis.
Journal of bacteriology. 2006 Sep; 188(17):6406-10. . PMID:16923908
Bacillus subtilis aconitase is required for efficient late-sporulation gene expression.
Journal of bacteriology. 2006 Sep; 188(17):6396-405. . PMID:16923907
Crystal structure of human iron regulatory protein 1 as cytosolic aconitase.
Structure (London, England : 1993). 2006 Jan; 14(1):129-39. . PMID:16407072
Regulation of citB expression in Bacillus subtilis: integration of multiple metabolic signals in the citrate pool and by the general nitrogen regulatory system.
Archives of microbiology. 2006 Mar; 185(2):136-46. . PMID:16395550
A comprehensive proteome map of growing Bacillus subtilis cells.
Proteomics. 2004 Oct; 4(10):2849-76. . PMID:15378759
Transcriptional profiling of gene expression in response to glucose in Bacillus subtilis: regulation of the central metabolic pathways.
Metabolic engineering. 2003 Apr; 5(2):133-49. . PMID:12850135
Complex regulation of the Bacillus subtilis aconitase gene.
Journal of bacteriology. 2003 Mar; 185(5):1672-80. . PMID:12591885
E. coli aconitase B structure reveals a HEAT-like domain with implications for protein-protein recognition.
Nature structural biology. 2002 Jun; 9(6):447-52. . PMID:11992126
CcpC, a novel regulator of the LysR family required for glucose repression of the citB gene in Bacillus subtilis.
Journal of molecular biology. 2000 Jan 28; 295(4):865-78. . PMID:10656796
Bacillus subtilis aconitase is an RNA-binding protein.
Proceedings of the National Academy of Sciences of the United States of America. 1999 Aug 31; 96(18):10412-7. . PMID:10468622
Anaerobic regulation of Bacillus subtilis Krebs cycle genes.
Journal of bacteriology. 1998 Jul; 180(13):3304-11. . PMID:9642180
A null mutation in the Bacillus subtilis aconitase gene causes a block in Spo0A-phosphate-dependent gene expression.
Journal of bacteriology. 1997 Dec; 179(23):7351-9. . PMID:9393699
2-Ketoglutarate and the regulation of aconitase and histidase formation in Bacillus subtilis.
Journal of bacteriology. 1984 Apr; 158(1):379-82. . PMID:6143742
Bacillus subtilis citB gene is regulated synergistically by glucose and glutamine.
Journal of bacteriology. 1985 Oct; 164(1):155-64. . PMID:2413006
Multiple regulatory sites in the Bacillus subtilis citB promoter region.
Journal of bacteriology. 1990 Sep; 172(9):5408-15. . PMID:2118511
A target for carbon source-dependent negative regulation of the citB promoter of Bacillus subtilis.
Journal of bacteriology. 1990 Feb; 172(2):835-44. . PMID:2105305
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Time of last update: 2025-07-25 01:24:31
Author of last update: Jstuelk