LeuB

• Description: 3-isopropylmalate dehydrogenase
  
  

Gene name	leuB
Synonyms	leuC
Essential	no
Product	3-isopropylmalate dehydrogenase
Function	biosynthesis of leucine
Gene expression levels in SubtiExpress: leuB
Metabolic function and regulation of this protein in SubtiPathways: Ile, Leu, Val, 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
Expression at a glance   PubMed

Categories containing this gene/protein

biosynthesis/ acquisition of amino acids, phosphoproteins

This gene is a member of the following regulons

CcpA regulon, CodY regulon, T-box, TnrA regulon

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:
  • phosphorylated on Arg-4 PubMed

• Cofactor(s):

• Effectors of protein activity:

• Interactions:

• Localization:

Database entries

• Structure: 1XAD (Thermus thermophilus)

• UniProt: P05645

• KEGG entry: [3]

• E.C. number: 1.1.1.85

Expression and regulation

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

• Expression browser: leuB PubMed

• Sigma factor: SigA PubMed

• Regulation: for a complete overview on the regulation of the ilv operon, see Brinsmade et al.
  • repressed by casamino acids PubMed
  • expression is stimulated in the presence of glucose 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:
  • CcpA: transcription activation PubMed
  • T-box: tRNA-controlled RNA switch that mediates termination/antitermination
  • TnrA: transcription repression PubMed
  • CodY: transcription repression PubMed

• Additional information:

Biological materials

• Mutant:
  • 1A618 ( leuB::erm), PubMed, available at BGSC

• Expression vector:

• lacZ fusion:

• GFP fusion:

• two-hybrid system:

• Antibody: