Plasmid-instability in acrA Mutants of Escherichia coli K12

Nakamura, Hakobu

doi:10.1099/00221287-84-1-85

Cited by 15 publications

(9 citation statements)

References 27 publications

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“…Yet, many genes involved in the processes of replication initiation or elongation were initially isolated through screens for mutants that exhibited impaired growth [33–39], or based on their inability to stably maintain plasmids [40–43]. These phenotypes closely resemble those seen in recBC and recD mutants, and suggest a function for RecBCD in the normal replication cycle of E. coli .…”

Section: A Role For Recbcd In Completing Replication Eventsmentioning

confidence: 99%

RecBCD is required to complete chromosomal replication: Implications for double-strand break frequencies and repair mechanisms

et al. 2015

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Several aspects of the mechanism of homologous double strand break repair remain unclear. Although intensive efforts have focused on how recombination reactions initiate, far less is known about the molecular events that follow. Based upon biochemical studies, current models propose that RecBCD processes double strand ends and loads RecA to initiate recombinational repair. However, recent studies have shown that RecBCD plays a critical role in completing replication events on the chromosome through a mechanism that does not involve RecA or recombination. Here, we examine several studies, both early and recent, that suggest RecBCD also operates late in the recombination process- after initiation, strand invasion, and crossover resolution have occurred. Similar to its role in completing replication, we propose a model in which RecBCD is required to resect and resolve the DNA synthesis associated with homologous recombination at the point where the missing sequences on the broken molecule have been restored. We explain how the impaired ability to complete chromosome replication in recBC and recD mutants is likely to account for the loss of viability and genome instability in these mutants, and conclude that spontaneous double strand breaks and replication fork collapse occur far less frequently than previously speculated.

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Section: A Role For Recbcd In Completing Replication Eventsmentioning

confidence: 99%

RecBCD is required to complete chromosomal replication: Implications for double-strand break frequencies and repair mechanisms

et al. 2015

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“…These results suggest that the acrA+ membrane protein is responsible for cellular sensitivity to AF. The acrA+ protein has also been implicated in the stability of F and R plasmids in the cell (Nakamura, 1974(Nakamura, , 1976.…”

Section: Introductionmentioning

confidence: 99%

Acriflavine-binding Capacity Controlled by the acrA Gene of Escherichia coli

Nakamura

Shinya

1985

Microbiology

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The acrA mutation in Escherichia coli led to a substantial increase of the acriflavine-binding capacity of the cell, whereas the related mutations acrB (gyrB) and arcC did not. Metal ions such as Na+, K+, Mg2+, Ca2+ and Al3+ effectively released the bound acriflavine, in proportion to their ionic strengths. The presence of cations, in fact, increased the survival fraction of the cells in the acriflavine-containing medium. Polymyxin B, an antibiotic which binds to membrane phospholipid, competed with acriflavine for binding sites. Cell wall digestion by treatment with lysozyme and EDTA slightly decreased the acriflavine-binding capacity. Almost no difference was observed in acriflavine-binding capacity between intact cells and cells from which lipopolysaccharide has been extracted (46.9% removed from the acrA cells and 47.4% from the acrA+ cells). Acriflavine bound to the cells was most effectively extracted by ethanol containing 1% HCl or by 2% (w/v) SDS. The difference in the acriflavine-binding capacity between the acrA and acrA+ cells was also observed in the spheroplasts. These facts indicate a relationship between the acrA gene product and the acriflavine-binding capacity of the cells.

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“…The acrA mutation, which is mapped at min 11 on the E, coli chromosome (Nakamura et al 1975), leads to deficiency of a membrane protein referred to as acrA+ protein (Nakamura and Suganuma 1972;Nishimukai et al 1973). Therefore, the above observation was interpretated as that the acrA+ protein of the host cell membrane is responsible for the replication of F factor (Nakamura 1974).…”

mentioning

confidence: 99%

“…It was reported previously that plasmid F-gal + in Escherichia coli K 12 cells is eliminated at a high frequency under various conditions when the host cells contained the mutated allele acrA than when it contained the wild type allele acrA+ (Nakamura 1974). The acrA mutation, which is mapped at min 11 on the E, coli chromosome (Nakamura et al 1975), leads to deficiency of a membrane protein referred to as acrA+ protein (Nakamura and Suganuma 1972;Nishimukai et al 1973).…”

mentioning

confidence: 99%