Disease relevance of dinB

• Remarkably, the umuC122::Tn5 allele of umuC, dinB, and certain forms of umuD gene products endow E. coli with the ability to withstand HU treatment (HUR) [1].
• In this paper we show that the gene is identical to dinB, an SOS gene previously localized near the lac locus at 8 min, the function of which was shown to be required for mutagenesis of nonirradiated lambda phage infecting UV-preirradiated bacterial cells (termed lambdaUTM for lambda untargeted mutagenesis) [2].
• Role of Pseudomonas aeruginosa dinB-Encoded DNA Polymerase IV in Mutagenesis [3].

High impact information on dinB

• We report that the SOS-inducible, error-prone DNA polymerase (pol) IV, encoded by dinB, is required for adaptive point mutation in the E. coli lac operon [4].
• In Escherichia coli, the dinB gene is required for the SOS-induced lambda untargeted mutagenesis pathway and confers a mutator phenotype to the cell when the gene product is overexpressed [5].
• Here we show that, depending upon the nature of the DNA damage and its sequence context, the two additional SOS-inducible DNA polymerases, Pol II (polB) and Pol IV (dinB), are also involved in error-free and mutagenic translesion synthesis (TLS) [6].
• Stationary-phase mutation in the bacterial chromosome: recombination protein and DNA polymerase IV dependence [7].
• Furthermore, merely increasing the dinP gene expression, without UV irradiation or any other DNA-damaging treatment, resulted in a strong enhancement of mutagenesis in F'lac plasmids; at most, 800-fold increase in the G6-to-G5 change [2].

Chemical compound and disease context of dinB

• Here we report that the Escherichia coli dinB gene is required for resistance to some DNA-damaging agents that form adducts at the N2-position of deoxyguanosine (dG) [8].
• Translesional synthesis past acetylaminofluorene-derived DNA adducts catalyzed by human DNA polymerase kappa and Escherichia coli DNA polymerase IV [9].
• Escherichia coli DNA polymerase IV incorporated 2-hydroxy-dATP opposite template guanine or thymine and 8-hydroxy-dGTP exclusively opposite adenine in vitro [10].

Biological context of dinB

• Thus, our results establish that E. coli has at least two distinct pathways for SOS-induced mutagenesis: one dependent on umuDC and the other on dinB/P [2].
• Furthermore, DNA damage induces expression of the lexA-dinB transcriptional unit but not that of the recA gene [11].
• The dinB operon and spontaneous mutation in Escherichia coli [12].
• Based on an analysis of the PAO1 genome sequence, P. aeruginosa contains a single Y family DNA polymerase encoded by the dinB gene [3].
• The purified DinR protein binds specifically to the promoter regions of three B. subtilis SOS genes: dinB, dinC, and recA [13].

Anatomical context of dinB

• SOS-independent induction of dinB transcription by beta-lactam-mediated inhibition of cell wall synthesis in Escherichia coli [14].

Associations of dinB with chemical compounds

• In addition, dinB and dinD in the presence of both nalidixic acid and H2O2 at the same time showed no synergistic responses [15].
• Induction of dinB transcription mediated by ceftazidime produces an increase in the reversion of a +1 Lac frameshift mutation [14].
• These cellular expression levels strongly affect -1 frameshifts induced by 4-NQO in runs of six guanine bases: mutagenicity was highest in the strain CC108, followed by strains YG2242 (chromosome deltadinB/F' dinB+), YG2247 (chromosome dinB+/F' deltadinB) and FC1243 (chromosome deltadinB/F' deltadinB) [16].
• We show that DinB (DNA polymerase IV) catalyses accurate TLS over one such N2-dG adduct (N2-furfuryl-dG), and that DinB and its mammalian orthologue, DNA polymerase kappa, insert deoxycytidine (dC) opposite N2-furfuryl-dG with 10-15-fold greater catalytic proficiency than opposite undamaged dG [8].

Regulatory relationships of dinB

• Polyphosphate kinase regulates error-prone replication by DNA polymerase IV in Escherichia coli [17].

Other interactions of dinB

• Reverse transcription-PCR analyses demonstrated that, in both cases, lexA and dinB constitute a single transcriptional unit [11].
• Inactivation of polB, dinB, and umuD,C genes coding for "SOS" DNA polymerases did not affect significantly the efficiency or fidelity of translesion synthesis [18].
• The fact that genes coding for translesion-synthesis (TLS) polymerases, particularly dinB and umuC homologs, have been conserved during evolution and the present analysis suggest that their activity is essential for the cellular survival and fitness [19].
• Possible roles of the P. aeruginosa dinB, polA, and polC gene products in mutagenesis are discussed [3].

Analytical, diagnostic and therapeutic context of dinB

• Site-directed mutagenesis experiments of dinB also demonstrate that the polymerase activity of DinB is required for its in vivo mutagenicity [5].

References