Disease relevance of dnaQ

• The Hot (homolog of theta) protein of bacteriophage P1 can substitute for the Escherichia coli DNA polymerase III theta subunit, as evidenced by its stabilizing effect on certain dnaQ mutants that carry an unstable polymerase III epsilon proofreading subunit (antimutator effect) [1].
• Mutants in the Exo I motif of Escherichia coli dnaQ: defective proofreading and inviability due to error catastrophe [2].

High impact information on dnaQ

• This MMS induction of dnaN and dnaQ gene expression is unrelated to the adaptive response [3].
• We found that DNA damage caused by the alkylating agent methyl methanesulphonate (MMS) leads to a significant induction in dnaN and dnaQ gene expression suggesting a requirement of increased amounts of at least some DNA polymerase III holoenzyme subunits for recovery from DNA damage caused by MMS [3].
• This gene, or one nearby, has been identified as the locus of suppressor mutations that promote growth by cells deleted for dnaQ, the gene for the editing subunit of this enzyme complex [4].
• We have studied spontaneous and UV mutagenesis of the glyU gene in Escherichia coli trpA461 (GAG) strains carrying the pIP11 plasmid, in which the dnaQ gene encoding the 3'-5' exonuclease subunit (epsilon) of DNA polymerase III is fused to the tac(trp-lac) promoter [5].
• Induction of a mutagenic stress situation by treatment with the base analogue 2-aminopurine (2-AP) leads to an increase in dnaQ transcription [6].

Biological context of dnaQ

• By promotor fusion to galK, gene fusion to lacZ and Sl analysis the in vivo regulation of dnaQ coding the proofreading subunit of DNA polymerase III holoenzyme was analyzed under conditions of induced or constitutive SOS expression [7].

Associations of dnaQ with chemical compounds

• Deoxynucleosides bearing isoadenine (2-aminopurine) and isoguanine (2-hydroxy-6-aminopurine) showed a high mutagenic potency towards the recombinant strains, to an extent comparable to that of the most efficient mutator alleles (dnaQ) [8].

Analytical, diagnostic and therapeutic context of dnaQ

• Two of the mutations, dnaQ186 and dnaQ231, were shown to be new alleles of the dnaQ gene by genetic mapping and complementation tests with the dnaQ49 mutation previously isolated [9].

References