The recombination initiation functions DprA and RecFOR suppress microindel mutations in Acinetobacter baylyi ADP1
Mikkel M Liljegren1, João A Gama1,2, Pål J Johnsen1
1Microbial Pharmacology and Population Biology Research Group, Department of Pharmacy, UiT The Arctic University of Norway, Tromsø, Norway.
Molecular Microbiology
|May 17, 2024
Summary
Short-Patch Double Illegitimate Recombination (SPDIR) is a rare mutation. DprA and RecA proteins work together to prevent these harmful microindel mutations, with DprA playing a key role in suppressing SPDIR.
Area of Science:
- Molecular Biology
- Genetics
- Microbiology
Background:
- Short-Patch Double Illegitimate Recombination (SPDIR) is a rare DNA mutation mechanism involving ectopic single-stranded DNA integration during replication.
- In Acinetobacter baylyi, genome maintenance proteins like RecA are known to control SPDIR by binding and inactivating single-stranded DNA.
- Upstream factors like DprA, RecFOR, and RecBCD are involved in loading RecA onto single-stranded DNA.
Purpose of the Study:
- To investigate the roles of DprA, RecFOR, and RecBCD in the control of SPDIR mutations.
- To elucidate the specific contribution of DprA in conjunction with RecA to suppress SPDIR.
- To understand the relationship between DprA's SPDIR-avoiding function and its role in natural transformation.
Main Methods:
- Comparative analysis of SPDIR mutation rates in wildtype and mutant strains of Acinetobacter baylyi.
- Genetic manipulation to create strains lacking DprA, RecA, or combinations thereof.
- Assessment of SPDIR mutation frequency in different genetic backgrounds.
Main Results:
- DprA, RecFOR, and RecBCD were all found to suppress SPDIR mutations in wildtype bacteria.
- Absence of DprA led to a slight increase in SPDIR mutations.
- Absence of both DprA and RecA resulted in a significant increase in SPDIR mutations, indicating a combined suppressive role.
- DprA's function in suppressing SPDIR was independent of its role in natural transformation.
Conclusions:
- DprA, in conjunction with RecA, plays a crucial role in preventing potentially harmful microindel mutations via SPDIR.
- The findings suggest a novel mechanism for genome stability involving DprA and RecA.
- This study provides a potential explanation for the widespread presence of the dprA gene in bacteria that do not undergo natural transformation.
Keywords:
Acinetobacter baylyiComADNA recombinationDprARecARecBCDRecFORillegitimate recombinationmicroindelsmutationMore Related Videos
Related Concept Videos
02:53Conservative Site-specific Recombination and Phase Variation
6.0K
Because the DNA segments are cut and reorganized in a direction-specific manner, site-specific recombination has emerged as an efficient genetic engineering technique. Flippase and Cyclization recombinases or Flp and Cre, respectively, are two members of the tyrosine recombinase family derived from bacteriophages, that are used to mediate site-specific DNA insertions, deletions, and targeted expression of proteins in mammalian cell lines.
The recognition sites for Cre recombinase called LoxP...
The recognition sites for Cre recombinase called LoxP...
6.0K
02:31Homologous Recombination
50.5K
The basic reaction of homologous recombination (HR) involves two chromatids that contain DNA sequences sharing a significant stretch of identity. One of these sequences uses a strand from another as a template to synthesize DNA in an enzyme-catalyzed reaction. The final product is a novel amalgamation of the two substrates. To ensure an accurate recombination of sequences, HR is restricted to the S and G2 phases of the cell cycle. At these stages, the DNA has been replicated already and the...
50.5K
02:37Restarting Stalled Replication Forks
5.8K
DNA replication is initiated at sites containing predefined DNA sequences known as origins of replication. DNA is unwound at these sites by the minichromosome maintenance (MCM) helicase and other factors such as Cdc45 and the associated GINS complex.The unwound single strands are protected by replication protein A (RPA) until DNA polymerase starts synthesizing DNA at the 5’ end of the strand in the same direction as the replication fork. To prevent the replication fork from falling apart,...
5.8K
02:32Exon Recombination
3.6K
The evolution of new genes is critical for speciation. Exon recombination, also known as exon shuffling or domain shuffling, is an important means of new gene formation. It is observed across vertebrates, invertebrates, and in some plants such as potatoes and sunflowers. During exon recombination, exons from the same or different genes recombine and produce new exon-intron combinations, which might evolve into new genes.
Exon shuffling follows “splice frame rules.” Each exon...
Exon shuffling follows “splice frame rules.” Each exon...
3.6K
01:02Long-patch Base Excision Repair
7.0K
Since the discovery of the two BER pathways, there has been a debate about how a cell chooses one pathway over the other and the factors determining this selection. Numerous in vitro experiments have pointed out multiple determinants for the sub-pathway selection. These are:
7.0K