Mdh

• Description: malate dehydrogenase
  
  

Gene name	mdh
Synonyms	citH
Essential	no
Product	malate dehydrogenase
Function	TCA cycle
Gene expression levels in SubtiExpress: mdh
Interactions involving this protein in SubtInteract: Mdh
Metabolic function and regulation of this protein in SubtiPathways: mdh
MW, pI	33 kDa, 4.727
Gene length, protein length	936 bp, 312 aa
Immediate neighbours	phoP, icd
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

carbon core metabolism, membrane proteins, phosphoproteins, most abundant proteins

This gene is a member of the following regulons

CcpA regulon, CcpC regulon

The gene

Basic information

• Locus tag: BSU29120

Database entries

• BsubCyc: BSU29120

• 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
  • specific activity: 0.56 µmol min^-1 (mg protein)^-1 PubMed

• Domains:

• Modification:
  • phosphorylated on Arg-156 PubMed
  • phosphorylation on Ser-149 PubMed

• Cofactors: NAD⁺

• 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
  • Mdh-Icd PubMed

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

Database entries

• BsubCyc: BSU29120

• Structure: 1EMD (E.coli)

• UniProt: P49814

• KEGG entry: [3]

• E.C. number: 1.1.1.37

Additional information

• The enzyme is a tetramer PubMed
• extensive information on the structure and enzymatic properties of Mdh can be found at Proteopedia

Expression and regulation

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

• Expression browser: 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:
  • belongs to the 100 most abundant proteins PubMed
  • number of protein molecules per cell (minimal medium with glucose and ammonium): 35291 PubMed
  • number of protein molecules per cell (complex medium with amino acids, without glucose): 58271 PubMed

Biological materials

• Mutant:
  • GP719(spc) & GP1150(spc), available in Jörg Stülke's lab
  • GP790 (citZ-icd-mdh::kan), available in Jörg Stülke's lab

• Expression vector:
  • pGP385: for expression, purification in E. coli with N-terminal His-tag, in pWH844, available in Jörg Stülke's lab
  • pGP1123 (N-terminal Strep-tag, for SPINE, purification from B. subtilis, in pGP380) (available in Jörg Stülke's lab)
  • pGP1755 (expression / purification of Mdh-S149A, with N-terminal His-tag from E. coli, in pWH844), available in Jörg Stülke's lab
  • pGP1764 (for expression, purification in E. coli with N-terminal Strep-tag, in pGP172, available in Jörg Stülke's lab)
  • GP1438(mdh-Strep (spc)) & GP1440(mdh-Strep (cat)), purification from B. subtilis, for SPINE, available in Jörg Stülke's lab

• lacZ fusion:

• GFP fusion: GP1431 (spc, based on pGP1870), available in Jörg Stülke's lab

• YFP fusion: GP1429 (spc, based on pGP1871), available in Jörg Stülke's lab

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

• Antibody:

• FLAG-tag construct:
  • GP1130 (spc, based on pGP1331), available in Jörg Stülke's lab