Integration Host Factor IHF facilitates homologous recombination and mutagenic processes in Pseudomonas putida.

Integration Host Factor IHF facilitates homologous recombination and mutagenic processes in Pseudomonas putida. DNA Repair (Amst). 2019 Nov 05;85:102745 Authors: Mikkel K, Tagel M, Ukkivi K, Ilves H, Kivisaar M Abstract Nucleoid-associated proteins (NAPs) such as IHF, HU, Fis, and H-NS alter the topology of bound DNA and may thereby affect accessibility of DNA to repair and recombination processes. To examine this possibility, we investigated the effect of IHF on the frequency of homologous recombination (HR) and point mutations in soil bacterium Pseudomonas putida by using plasmidial and chromosomal assays. We observed positive effect of IHF on the frequency of HR, whereas this effect varied depending both on the chromosomal location of the HR target and the type of plasmid used in the assay. The occurrence of point mutations in plasmid was also facilitated by IHF, whereas in the chromosome the positive effect of IHF appeared only at certain DNA sequences and/or chromosomal positions. We did not observe any significant effects of IHF on the spectrum of mutations. However, despite of the presence or absence of IHF, different mutational hot spots appeared both in plasmid and in chromosome. Additionally, the frequency of frameshift mutations in the chromosome was also strongly affected by the location of the mutational target sequence. Taking together, our results indicate that IHF facilitates the occurrence of genetic changes in P. pu...
Source: DNA Repair - Category: Genetics & Stem Cells Authors: Tags: DNA Repair (Amst) Source Type: research