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: leuB
MW, pI	39 kDa, 4.744
Gene length, protein length	1095 bp, 365 aa
Immediate neighbours	leuC, leuA
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

biosynthesis/ acquisition of amino acids, phosphoproteins, most abundant proteins

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

• BsubCyc: BSU28270

• 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

• Cofactors:

• Effectors of protein activity:

• Interactions:

• Localization:

Database entries

• BsubCyc: BSU28270

• 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:
  • belongs to the 100 most abundant proteins PubMed
  • number of protein molecules per cell (minimal medium with glucose and ammonium): 6438 PubMed
  • number of protein molecules per cell (complex medium with amino acids, without glucose): 942 PubMed
  • number of protein molecules per cell (minimal medium with glucose and ammonium, exponential phase): 5218 PubMed
  • number of protein molecules per cell (minimal medium with glucose and ammonium, early stationary phase after glucose exhaustion): 2316 PubMed
  • number of protein molecules per cell (minimal medium with glucose and ammonium, late stationary phase after glucose exhaustion): 1868 PubMed

Biological materials

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

• Expression vector:

• lacZ fusion:

• GFP fusion:

• two-hybrid system:

• Antibody: