IlvB

• Description: acetolactate synthase (large subunit)
  
  

Gene name	ilvB
Synonyms
Essential	no
Product	acetolactate synthase (large subunit)
Function	biosynthesis of branched-chain amino acids
MW, pI	62 kDa, 5.178
Gene length, protein length	1722 bp, 574 aa
Immediate neighbours	ilvH, ysnD
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: BSU28310

Database entries

• DBTBS entry: [1]

• SubtiList entry: [2]

The protein

Basic information/ Evolution

• Catalyzed reaction/ biological activity: 2 pyruvate = 2-acetolactate + CO₂ (according to Swiss-Prot)

• Protein family: TPP enzyme family (according to Swiss-Prot)

• Paralogous protein(s):

Extended information on the protein

• Kinetic information:

• Domains:

• Modification:

• Cofactor(s):

• Effectors of protein activity:

• Interactions:

• Localization:

Database entries

• Structure: 1N53 (T box RNA)

• Swiss prot entry: P37251

• KEGG entry: [3]

• E.C. number: 2.2.1.6

Additional information

• subject to Clp-dependent proteolysis upon glucose starvation PubMed

Expression and regulation

• Operon: ilvB-ilvH-ilvC-leuA-leuB-leuC-leuD PubMed

• Sigma factor: SigA PubMed

• Regulation: repressed by casamino acids PubMed, repressed by CodY PubMed, expressed in the absence of branched-chain amino acids (BCAA), expression is stimulated in the presence of glucose (CcpA) PubMed, during growth repressed under nitrogen limiting conditions (TnrA) PubMed
  • repressed in the absence of good nitrogen sources (glutamine or ammonium) (TnrA) PubMed
  • repressed during growth in the presence of branched chain amino acids (CodY) PubMed

• Regulatory mechanism: glucose regulation: CcpA PubMed, TnrA: transcription repession PubMed, repression by BCAA: tRNA-controlled RNA switch (T-box) that mediates termination/antitermination, CodY: transcription repression PubMed1 PubMed2
  • TnrA: transcription repression PubMed
  • CodY: transcription repression PubMed

• Additional information: subject to Clp-dependent proteolysis upon glucose starvation PubMed

Biological materials

• Mutant: GP324, ilvB under control of pXyl (cat), available in Jörg Stülke lab

• Expression vector:

• lacZ fusion:

• GFP fusion:

• two-hybrid system:

• Antibody:

References

1. Mäder et al. (2002) Transcriptome and Proteome Analysis of Bacillus subtilis Gene Expression Modulated by Amino Acid Availability. J. Bacteriol 184: 1844288-4295 PubMed
2. Gerth et al. (2008) Clp-dependent proteolysis down-regulates central metabolic pathways in glucose-starved Bacillus subtilis. J Bacteriol 190:321-331 PubMed
3. Grandoni, J. A., S. A. Zahler, and J. M. Calvo. 1992. Transcriptional regulation of the ilv-leu operon of Bacillus subtilis. J. Bacteriol. 174:3212-3219. PubMed
4. Ludwig, H., Meinken, C., Matin, A. & Stülke, J. (2002) Insufficient expression of the ilv-leu operon encoding enzymes of branched-chain amino acids biosynthesis limits growth of a Bacillus subtilis ccpA mutant. J. Bacteriol. 184: 5174-5178. PubMed
5. Shivers RP, Sonenshein AL: Bacillus subtilis ilvB operon: an intersection of global regulons. Mol Microbiol 2005, 56:1549-1559. PubMed
6. Tojo S, Satomura T, Morisaki K, Deutscher J, Hirooka K, Fujita Y: Elaborate transcription regulation of the Bacillus subtilis ilv-leu operon involved in the biosynthesis of branched-chain amino acids through global regulators of CcpA, CodY and TnrA. Mol Microbiol 2005, 56:1560-1573. PubMed
7. Tojo S, Satomura T, Morisaki K, Yoshida KI, Hirooka K, Fujita Y: Negative transcriptional regulation of the ilv-leu operon for biosynthesis of branched-chain amino acids through the Bacillus subtilis global regulator TnrA. J Bacteriol 2004, 186:7971-7979. PubMed
8. Author1, Author2 & Author3 (year) Title Journal volume: page-page. PubMed