Abstract
Acinetobacter baumannii is an opportunistic pathogen causing several infections that are increasingly diSicult to treat due to its ability to rapidly gain antibiotic resistances. These resistances can arise due to mutations during the DNA damage response (DDR), through the activity of error-prone DNA polymerases, such as DNA polymerase V (DNA Pol V). Currently, the DDR in A. baumannii is not well understood and the regulation of genes encoding multiple copies of DNA Pol V is not fully characterized. Through genome wide mutagenesis, we have identified a novel TetR-like family regulator of genes that encode DNA Pol V, which we have named Error-prone polymerase regulator, EppR. We have found that EppR represses the expression of the genes encoding DNA Pol V and itself through direct binding to a conserved EppR motif in their promoters. Lastly, we show that EppR also regulates UmuDAb, previously identified as a regulator of genes encoding DNA Pol V. These two gene products are functionally required to ensure regulation of expression of genes encoding DNA Pol Vs and umuDAb. With these results, we propose a co-repressor model for the regulation of genes encoding DNA Pol V and umuDAb.
Competing Interest Statement
The authors have declared no competing interest.
Footnotes
Competing Interest Statement
The authors declare no competing interest.
Abbreviations
- DDR
- DNA damage response
- EMSA
- Electrophoretic mobility shift assay
- EppR
- Error-prone polymerase regulator
- MMS
- Methyl methanesulfonate
- TSS
- Transcription start site
- WT
- Wild-type; Acinetobacter baumannii ATCC17978