Part:BBa_I718004

DapA Coli MG1655

dapA (Dihydrodipicolinate synthase) is an essential gene in the lysine and the peptidoglycan biosynthesis pathways. Strains mutated in the gene are auxotroph for DAP (LL, diaminopimelate).

The expression of dapA is controled by the dapAp promoter (see part I71800x), whose activity is regulated by DAP concentration through an unknown mechanism. Lysine is also known to have an allosteric feedback effect on the DapA protein, inhibiting its activity.

The lysine pathway is pretty well conserved across all kingdoms. In plants, DAP is only an intermediate in the lysine biosynthesis. There is no constitutive need for DAP, and there is a strong negative feedback of lysine on DapA. On the other side, gram+ bacteria which have a thick cell wall, present a strong need for DAP for the peptidoglycan synthesis without respect to the lysine concentration. Gram+ DapA genes are thus insensitive to lysine. Gram– bacteria which have a smaller cell wall, also have a smaller need for DAP, which is consistent with the fact that there is a medium negative feedback from lysine on gram- DapA.

Info from Ecocyc:

Dihydrodipicolinate synthase is the first enzyme unique to lysine biosynthesis, catalyzing the condensation of pyruvate and aspartate β-semialdehyde by a ping-pong mechanism. It also catalyzes the rate-limiting step in E.coli lysine biosynthesis after aspartate kinase III. The condensing enzyme-pyruvate complex, prior to reduction and hydrolysis, exists as the Schiff base formed between the carbonyl of pyruvate and an ε-amino group of a lysine residue on the enzyme. This property classifies the enzyme as a Class I aldolase with respect to carbon-carbon bond formation. The enzyme is inhibited by lysine, a feedback inhibitor.

For more info see:

http://biocyc.org/ECOLI/NEW-IMAGE?type=PATHWAY&object=DAPLYSINESYN-PWY http://biocyc.org/ECOLI/NEW-IMAGE?type=ENZYME-IN-PATHWAY&object=DIHYDRODIPICSYN-CPLX

• Relation Between Excreted Lipopolysaccharide Complexes and Surface Structures of a Lysine-Limited Culture of Escherichia coli K. W. KNOX,' MARET VESK,2 AND ELIZABETH WORK
• Soybean DapA mutations encoding lysine-insensitive dihydrodipicolinate synthase Gregg W. Silk and Benjamin F. Matthews
• Expression from the Escherichia coli dapA promoter is regulated by intracellular levels of diaminopimelic acid. Acord J, Masters M (2004), FEMS Microbiol Lett 235(1);131-7. PMID: 15158272

Sequence and Features

Assembly Compatibility:

• 10
  COMPATIBLE WITH RFC[10]
• 12
  INCOMPATIBLE WITH RFC[12]

  Illegal NheI site found at 64
  
• 21
  COMPATIBLE WITH RFC[21]
• 23
  COMPATIBLE WITH RFC[23]
• 25
  COMPATIBLE WITH RFC[25]
• 1000
  COMPATIBLE WITH RFC[1000]