Mdh

• Description: malate dehydrogenase
  
  

Gene name	mdh
Synonyms	citH
Essential	no
Product	malate dehydrogenase
Function	TCA cycle
Metabolic function and regulation of this protein in SubtiPathways: Central C-metabolism
MW, pI	33 kDa, 4.727
Gene length, protein length	936 bp, 312 aa
Immediate neighbours	phoP, icd
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: BSU29120

Database entries

• DBTBS entry: [1]

• SubtiList entry: [2]

The protein

Basic information/ Evolution

• Catalyzed reaction/ biological activity: (S)-malate + NAD⁺ = oxaloacetate + NADH (according to Swiss-Prot)

• Protein family: MDH type 3 family (according to Swiss-Prot)

• Paralogous protein(s):

Extended information on the protein

• Kinetic information: Reversible Michaelis-Menten PubMed

• Domains:

• Modification: phosphorylation on Ser-149 PubMed

• Cofactor(s):

• Effectors of protein activity:
  • Inhibited by Mg2+, Ca2+, Zn2+, Ag2+ and Hg2+ PubMed PubMed
  • Inhibited by oxaloacetate (above 1mM) and malate (above 7,7mM) PubMed

• Interactions:
  • CitZ-Mdh-Icd (this is the core of the TCA cycle metabolon) PubMed
  • Mdh-PckA (this interaction occurs under gluconeogenic, but not under glycolytic conditions) PubMed
  • Mdh-Ndh PubMed
  • Mdh-CitB PubMed
  • Mdh-CitG PubMed
  • Mdh-SucC PubMed

• Localization: cytoplasm (according to Swiss-Prot), membrane associated PubMed

Database entries

• Structure: 1EMD (E.coli)

• UniProt: P49814

• KEGG entry: [3]

• E.C. number: 1.1.1.37

Additional information

The enzyme is a tetramer PubMed

Expression and regulation

• Operon:
  • citZ-icd-mdh PubMed
  • icd-mdh PubMed

• Sigma factor:
  • citZ: SigA PubMed
  • icd: SigA PubMed

• Regulation:
  • citZ: catabolite repression (CcpA) PubMed
  • citZ: repression by glucose + glutamate (CcpC) PubMed
  • mdh: constitutive

• Regulatory mechanism:
  • CcpA: transcription repression, CcpC: transcription repression PubMed
  • CcpC: transcription repression (molecular inducer: citrate) PubMed

• Additional information:

Biological materials

• Mutant: GP719 (spc), available in Stülke lab

• Expression vector:
  • pGP1123 (N-terminal Strep-tag, for SPINE, purification from B. subtilis, in pGP380) (available in Stülke lab)
  • for expression, purification in E. coli with N-terminal His-tag, in pWH844: pGP385, available in Stülke lab
  • pGP1755 (expression / purification of Mdh-S149A, with N-terminal His-tag from E. coli, in pWH844), available in Stülke lab

• lacZ fusion:

• GFP fusion:

• two-hybrid system: B. pertussis adenylate cyclase-based bacterial two hybrid system (BACTH), available in Stülke lab

• Antibody: