Disease relevance of dnaE

• The polymerase subunit of DNA polymerase III of Escherichia coli. I. Amplification of the dnaE gene product and polymerase activity of the alpha subunit [1].
• A novel Bacillus subtilis gene, antE, temporally regulated and convergent to and overlapping dnaE [2].
• We report that Vibrio cholerae (Vc) contains a gene homologous to Escherichia coli dnaE, the structural gene for the alpha (catalytic) subunit of replicative DNA polymerase III (PolIII) [3].
• We isolated and characterized temperature-sensitive mutants for two genes, dnaE and polC, that are essential for DNA replication in Staphylococcus aureus [4].
• We report that the N- and C-terminal splicing domains of the intein found in the dnaE gene of Synechocystis sp. PCC6803 (Ssp DnaE intein) are capable of association in vivo and in vitro, even with key splicing residues changed to alanine (Cys(1), Asn(159), and Cys(+1) to Ala) [5].

High impact information on dnaE

• Synthesis of a mature DnaE protein is predicted to involve expression of two split dnaE genes followed by two protein cis-splicing reactions and one protein trans-splicing reaction [6].
• To elucidate the role of the alpha subunit, the catalytic subunit of the polymerase, in maintaining the high fidelity of DNA replication, we isolated a mutator mutant, the mutation (dnaE173) of which resides on the dnaE gene, encoding the alpha subunit [7].
• The Escherichia coli dnaE gene, which encodes the alpha subunit of DNA polymerase III (pol III) holoenzyme, has been cloned in a plasmid containing the PL promoter of phage lambda and thermally induced to overproduce the alpha subunit [1].
• We have now determined the 1809-base pair sequence of the dnaE coding region, which precedes rpoD and is transcribed in the same counterclockwise direction on the chromosome [8].
• The mutation lies in the dnaE gene coding for the alpha subunit of polymerase III: it is a Gly to Asp change at codon 133 [9].

Biological context of dnaE

• In contrast, mutations in the C-terminal site exhibited near wild-type phenotypes. alpha Subunits with the C-terminal site completely removed could participate in processive DNA replication, could bind beta2, and, if induced to high level expression, could complement a temperature-sensitive conditional lethal dnaE mutation [10].
• A restriction map of the dnaE gene and the surrounding 10.7-kilobase region of the E. coli chromosome was determined [11].
• The transcript from promoter Px codes for a small protein with partial homology to the OmpR protein from Escherichia coli and also carries an untranslated sequence at its 3' end that is complementary to the 5' end of the P3 transcript, which codes for the ribosome binding site of dnaE [2].
• The mutant phenotypes are due to single amino acid substitutions in the alpha subunit, the protein product of the dnaE (polC) gene [12].
• In recA441 lexA51 strains where the SOS system is constitutively expressed, the UV mutator effect of the dnaE alleles was similar in relative terms (though greater in absolute terms) [13].

Associations of dnaE with chemical compounds

• Conjugational synthesis accompanying transfer involving the combination of dnaE (ts) thymine dependent and thymine independent donor and recipient strains measured by incorporation of 14C thymine was observed at the restrictive temperature [14].
• However, like the complete reaction, residual synthesis occurs at the replication fork pre-existing in vivo at the time of toluenization, produces short and long pieces of DNA, is inhibited by arabinosyl-adenine triphosphate, azide or mitomycin C, and is dependent on the dnaE, DNAB and dnaG gene products [15].

Analytical, diagnostic and therapeutic context of dnaE

• Sequence analysis of the Escherichia coli dnaE gene [16].
• In vivo complementation tests indicated that this mutation, dnaE9, lies in dnaE, the structural gene for DNA polymerase III [17].

References