Study of involvement of ImuB and DnaE2 in stationary-phase mutagenesis in Pseudomonas putida.
Several bacterial species carry in their genomes a so-called "mutagenesis" gene cluster encoding ImuB which is similar to Y-family DNA polymerases, and DnaE2 related to the catalytic subunit DnaE of Pol III. Y-family DNA polymerases are known to be involved in stationary-phase mutagenesis and DnaE2 homologues characterized so far have expressed a mutator phenotype. In this study, we raised a question about the involvement of ImuB and DnaE2 in stationary-phase mutagenesis. Here, we show that Pseudomonas putida ImuB and DnaE2 have antagonistic effects on stationary-phase mutagenesis. ImuB facilitated accumulation of stationary-phase mutants up to two-fold. In contrast to that, DnaE2 had no significant effect on emergence of 1-bp deletion mutants and moreover, it acted as an anti-mutator in accumulation of base substitution mutants in starving bacteria. Similar antagonistic effects of DnaE2 and ImuB on mutagenesis appeared also in UV-mutagenesis study. This data distinguishes the DnaE2 of P. putida from its homologues studied in other organisms.
Koorits
Lauri
L
Department of Genetics, Institute of Molecular and Cell Biology, Tartu University and Estonian Biocentre, 23 Riia Street, 51010 Tartu, Estonia.
Tegova
Radi
R
Tark
Mariliis
M
Tarassova
Kairi
K
Tover
Andres
A
Kivisaar
Maia
M
D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D004249:DNA Damage; D004260:DNA Repair; D017353:Gene Deletion; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D005821:Genetic Techniques; D008957:Models, Genetic; D016296:Mutagenesis; D009154:Mutation; D016958:Pseudomonas putida / Q000378:metabolism*; D013997:Time Factors; D014466:Ultraviolet Rays
D001426:Bacterial Proteins