LeuB

• Description: 3-isopropylmalate dehydrogenase
  
  

Gene name	leuB
Synonyms	leuC
Essential	no
Product	3-isopropylmalate dehydrogenase
Function	biosynthesis of leucine
Metabolic function and regulation of this protein in SubtiPathways: Coenzyme A
MW, pI	39 kDa, 4.744
Gene length, protein length	1095 bp, 365 aa
Immediate neighbours	leuC, leuA
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: BSU28270

Database entries

• DBTBS entry: [1]

• SubtiList entry: [2]

The protein

Basic information/ Evolution

• Catalyzed reaction/ biological activity: (2R,3S)-3-isopropylmalate + NAD⁺ = 4-methyl-2-oxopentanoate + CO₂ + NADH (according to Swiss-Prot)

• Protein family: LeuB type 1 subfamily (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: 1XAD (Thermus thermophilus)

• Swiss prot entry: P05645

• KEGG entry: [3]

• E.C. number: 1.1.1.85

Expression and regulation

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

• Sigma factor: SigA PubMed

• Regulation: repressed by casamino acids PubMed , expressed in the absence of branched-chain amino acids (BCAA), expression is stimulated in the presence of glucose PubMed, repressed by CodY 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: CodY: transcription repression PubMed, glucose regulation: CcpA PubMed, repression by BCAA: tRNA-controlled RNA switch (T-box) that mediates termination/antitermination
  • TnrA: transcription repression PubMed
  • CodY: transcription repression PubMed

• Additional information:

Biological materials

• Mutant:

• Expression vector:

• lacZ fusion:

• GFP fusion:

• two-hybrid system:

• Antibody:

References

Ana Gutiérrez-Preciado, Tina M Henkin, Frank J Grundy, Charles Yanofsky, Enrique Merino
Biochemical features and functional implications of the RNA-based T-box regulatory mechanism.
Microbiol Mol Biol Rev: 2009, 73(1);36-61
[PubMed:19258532] [WorldCat.org] [DOI] (I p)

Shigeo Tojo, Takenori Satomura, Kanako Kumamoto, Kazutake Hirooka, Yasutaro Fujita
Molecular mechanisms underlying the positive stringent response of the Bacillus subtilis ilv-leu operon, involved in the biosynthesis of branched-chain amino acids.
J Bacteriol: 2008, 190(18);6134-47
[PubMed:18641142] [WorldCat.org] [DOI] (I p)

Shigeo Tojo, Takenori Satomura, Kaori Morisaki, Ken-Ichi Yoshida, Kazutake Hirooka, Yasutaro Fujita
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(23);7971-9
[PubMed:15547269] [WorldCat.org] [DOI] (P p)

Ulrike Mäder, Susanne Hennig, Michael Hecker, Georg Homuth
Transcriptional organization and posttranscriptional regulation of the Bacillus subtilis branched-chain amino acid biosynthesis genes.
J Bacteriol: 2004, 186(8);2240-52
[PubMed:15060025] [WorldCat.org] [DOI] (P p)

Virginie Molle, Yoshiko Nakaura, Robert P Shivers, Hirotake Yamaguchi, Richard Losick, Yasutaro Fujita, Abraham L Sonenshein
Additional targets of the Bacillus subtilis global regulator CodY identified by chromatin immunoprecipitation and genome-wide transcript analysis.
J Bacteriol: 2003, 185(6);1911-22
[PubMed:12618455] [WorldCat.org] [DOI] (P p)

Holger Ludwig, Christoph Meinken, Anastasija Matin, Jörg Stülke
Insufficient expression of the ilv-leu operon encoding enzymes of branched-chain amino acid biosynthesis limits growth of a Bacillus subtilis ccpA mutant.
J Bacteriol: 2002, 184(18);5174-8
[PubMed:12193635] [WorldCat.org] [DOI] (P p)

Ulrike Mäder, Georg Homuth, Christian Scharf, Knut Büttner, Rüdiger Bode, Michael Hecker
Transcriptome and proteome analysis of Bacillus subtilis gene expression modulated by amino acid availability.
J Bacteriol: 2002, 184(15);4288-95
[PubMed:12107147] [WorldCat.org] [DOI] (P p)

F J Grundy, T M Henkin
Conservation of a transcription antitermination mechanism in aminoacyl-tRNA synthetase and amino acid biosynthesis genes in gram-positive bacteria.
J Mol Biol: 1994, 235(2);798-804
[PubMed:8289305] [WorldCat.org] [DOI] (P p)