HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via Google Scholar Google Scholar Articles by Kickstein, E. Articles by Wackernagel, W. Search for Related Content PubMed PubMed Citation Articles by Kickstein, E. Articles by Wackernagel, W. Agricola Articles by Kickstein, E. Articles by Wackernagel, W.

Deletions of recBCD or recD influence genetic transformation differently and are lethal together with a recJ deletion in Acinetobacter baylyi

Genetics, Department of Biology and Environmental Sciences, Carl von Ossietzky University Oldenburg, D-26111 Oldenburg, Germany

Correspondence
Wilfried Wackernagel
wilfried.wackernagel{at}uni-oldenburg.de

In prokaryotes, homologous recombination is essential for the repair of genomic DNA damage and for the integration of DNA taken up during horizontal gene transfer. In Escherichia coli, the exonucleases RecJ (specific for 5' single-stranded DNA) and RecBCD (degrades duplex DNA) play important roles in recombination and recombinational double-strand break (DSB) repair by the RecF and RecBCD pathways, respectively. The cloned recJ of Acinetobacter baylyi partially complemented an E. coli recJ mutant, suggesting functional similarity of the enzymes. A recJ mutant of A. baylyi was only slightly altered in transformability and was not affected in UV survival. In contrast, a recBCD mutant was UV-sensitive, and had a low viability and altered transformation. Compared to wild-type, transformation with large chromosomal DNA fragments was decreased about 5-fold, while transformation with 1.5 kbp DNA fragments was increased 3.3- to 7-fold. A recD mutation did not affect transformation, viability or UV resistance. However, double mutants recJ recBCD and recJ recD were non-viable, suggesting that the RecJ DNase or the RecBCD DNase (presumably absent in recD) becomes essential for the recombinational repair of spontaneously inactivated replication forks if the other DNase is absent. A model of recombination during genetic transformation is discussed in which the two ends of the single-stranded donor DNA present in the cytoplasm frequently integrate separately and often with a time difference. If replication runs through that genomic region before both ends of the donor DNA are ligated to recipient DNA, a double-strand break (DSB) is formed. In these cases, transformation becomes dependent on DSB repair.

This article has been cited by other articles:

				N. Hulter and W. Wackernagel Frequent integration of short homologous DNA tracks during Acinetobacter baylyi transformation and influence of transcription and RecJ and SbcCD DNases Microbiology, December 1, 2008; 154(12): 3676 - 3685. [Abstract] [Full Text] [PDF]

				K. Harms and W. Wackernagel The RecBCD and SbcCD DNases suppress homology-facilitated illegitimate recombination during natural transformation of Acinetobacter baylyi Microbiology, August 1, 2008; 154(8): 2437 - 2445. [Abstract] [Full Text] [PDF]

				A. Chakravorty, M. Klovstad, G. Peterson, R. E. Lindeman, and L. A. Gregg-Jolly Sensitivity of an Acinetobacter baylyi mpl Mutant to DNA Damage Appl. Envir. Microbiol., February 15, 2008; 74(4): 1273 - 1275. [Abstract] [Full Text] [PDF]