Disease relevance of dnaN

• Tandem transcription termination sites in the dnaN gene of Escherichia coli [1].
• A Bacillus subtilis dnaG mutant harbours a mutation in a gene homologous to the dnaN gene of Escherichia coli [2].
• At 41 degrees C, multiplication of filamentous (inovirid) phages M13 and fd was restricted specifically in HC138 F+ dnaN bacteria [3].
• When dnaN cells lysogenic for lambda i21 were grown at 42.5 degrees C for 60 min and then shifted down to 33 degrees C, a burst of lambda i21 occurred with concomitant cellular lysis, manifesting induction of the prophage development [3].
• A specialized transducing lambda phage carrying the dnaN genes of Escherichia coli specifies two proteins of about 41 and 48 kilodaltons (kd) [4].

High impact information on dnaN

• Characterization of dnaA and dnaN mutations that result in a constitutively high expression of RNR reveal this mechanism [5].
• Stationary phase induction of dnaN and recF, two genes of Escherichia coli involved in DNA replication and repair [6].
• Induction of dnaN and dnaQ gene expression in Escherichia coli by alkylation damage to DNA [7].
• Four group II introns were found in an unusually intron-rich dnaN gene (encoding the beta subunit of DNA polymerase III) of the cyanobacterium Trichodesmium erythraeum, and they have strong similarities to two introns of the RIR gene (encoding ribonucleotide reductase) of the same organism [8].
• The dnaN* transcript was shown to be induced upon treatment with nalidixic acid, and transcriptional dnaN*-cat gene fusions were UV inducible, suggesting induction of dnaN* at the transcriptional level [9].

Biological context of dnaN

• These results indicate that the dnaN and recF genes are organized in an operon [10].
• The one closest to the dnaN structural gene is the weakest, but it provides sufficient dnaN expression for complementation when the gene is present on a multicopy plasmid [10].
• However, a deletion inactivating dnaN without changing the reading frame of the gene does not affect expression of the recF gene [10].
• We have characterized the regulatory region of the dnaN gene by screening DNA restriction fragments for promoter activity, S1 mapping of mRNAs, deletion analysis, and in vivo dnaN complementation tests [10].
• The nucleotide sequence of the dnaA gene and the first 10% of the dnaN gene was determined [11].

Associations of dnaN with chemical compounds

• The protein encoded by dnaN was observed as a band on a polyacrylamide gel from minicells [12].

Other interactions of dnaN

• There are at least three dnaN promoters located in the second half of the dnaA coding region [10].
• We have determined the sequence of a 1498 base-pair region in E. coli that extends from within dnaN through recF and into the gyrB gene [13].
• Expression of the dnaN and dnaQ genes of Escherichia coli is inducible by mitomycin C [14].
• Analysis of translational gene fusions of the dnaN gene, encoding the beta subunit, to the lacZ reporter gene showed induction of beta-galactosidase activity upon UV irradiation of cells harboring the fusion plasmids [15].

Analytical, diagnostic and therapeutic context of dnaN

• The initiation codon and the Shine-Dalgarno sequence of dnaN* were identified by site-directed mutagenesis [9].

References