Radiation-sensitive and recombinationless mutants of salmonella typhimurium

Eisenstark, A.; Eisenstark, Roma; Dillewijn, J. van; Rörsch, A.

doi:10.1016/0027-5107(69)90066-9

Cited by 38 publications

(11 citation statements)

References 5 publications

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“…Transductional recombination is mediated by the RecBCD enzyme (11,21), which presumably enters the ends of the transduced DNA and degrades much of the fragment prior to stimulating exchange at Chi (Fig. 1).…”

Section: Discussionmentioning

confidence: 99%

Salmonella recD mutations increase recombination in a short sequence transduction assay

Miesel

Roth

1994

J Bacteriol

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We have identified recD mutants of Salmonella typhimurium by their ability to support growth of phage P22 abc (anti-RecBCD) mutants, whose growth is prevented by normal host RecBCD function. As in Escherichia coli, the recD gene ofS. typhimurium lies between the recB and argA genes at min 61 of the genetic map. Plasmids carrying the Salmonella recBCD+ genes restore ATP-dependent exonuclease V activity to an E. coli recBCD deletion mutant. The new Salmonella recD mutations (placed on this plasmid) eliminate the exonuclease activity and enable the plasmid-bearing E. coli deletion mutant to support growth of phage T4 gene 2 mutants. The Salmonella recD mutations caused a 3-to 61-fold increase in the ability of a recipient strain to inherit (by transduction) a large inserted element (MudA prophage; 38 kb). In this cross, recombination events must occur in the short (3-kb) sequences that flank the element in the 44-kb transduced fragment. The effect of the recD mutation depends on the nature of the flanking sequences and is likely to be greatest when those sequences lack a Chi site. The recD mutation appears to minimize fragment degradation and/or cause RecBC-dependent recombination events to occur closer to the ends of the transduced fragment. The effect of a recipient recD mutation was eliminated if the donor P22 phage expressed its Abc (anti-RecBC) function. We hypothesize that in standard (high multiplicity of infection) P22-mediated transduction crosses, recombination is stimulated both by Chi sequences (when present in the transduced fragment) and by the phage-encoded Abc protein which inhibits the host RecBCD exonuclease.The recB, recC, and recD genes of Escherichia coli and Salmonella typhimurium encode subunits of exonuclease V and provide a major bacterial recombination function (1,4,23,25,26,33,39,61). This enzyme also contributes to maintenance of cell viability and DNA repair. The RecBCD enzyme has several in vitro activities: a highly processive ATP-dependent double-stranded exonuclease and helicase, an ATP-dependent single-stranded exonuclease, and an ATP-stimulated endonuclease. The enzyme recognizes a specific DNA base sequence (Chi) and responds by mediating exchanges nearby (32, 58; reviewed in references 29, 49, and 53).E. coli strains that carry a recB or recC null mutation are deficient for all of the identified RecBCD enzymatic activities and display multiple phenotypic defects (30,31,33,57). Because of their deficiency in DNA damage repair, recBC mutants are sensitive to mitomycin and UV light; they also show reduced cell viability and reduced transductional and conjugational recombination (12,23). E. coli strains that carry recD mutations lack all exonuclease activity but retain the ATP-dependent helicase (1, 9, 29, 41, 43). These mutants show only a slight elevation of recombination ability (9, 34). Although recD mutants are recombination proficient, the recombination that they perform is independent of Chi sites, and the exchanges are localized near double-stranded ends (9,55,56).A model wh...

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Section: Discussionmentioning

confidence: 99%

Salmonella recD mutations increase recombination in a short sequence transduction assay

Miesel

Roth

1994

J Bacteriol

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“…The basis for this was to verify that, with increasing time, there was increasing variance in phenotypes. For decades, experiments using these archived mutants have provided interesting insights on genomic changes that occur in assumed dormancy [1][2][3][4][5][6]11]. In our most recent set of experiments, we focused on scoring three specific phenotypic changes:…”

Section: Resultsmentioning

confidence: 99%

“…+ legend Among studies in our laboratory of decades-old archived cultures of resting stage Salmonella typhimurium LT2, we have observed a series of diverse mutation patterns. The mutations included deletions, duplications, frame shifts, inversions and transpositions, and losses in carbon and nitrogen metabolism [1][2][3][4][5][6].…”

Section: Introductionmentioning

confidence: 99%

The Immortal Salmonella typhimurium. (Amnesia among Resting Cells)

Eisenstark

Ransdell

2017

JBMOA

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Our laboratory contains a collection of thousands of Salmonella typhimurium LT2 and LT7cultures, including mutants (the Demerec collection). Milislav Demerec started the collection of mutants over five decades ago at Carnegie Institute of Genetics, Cold Spring Harbor, L.I., NY. Upon his retirement, Dr. Demerec and the collection moved to Brookhaven National Laboratories. Upon Dr. Demerec's death, the collection (archived in quintuplicate) was divided and distributed to Kenneth Sanderson (who now maintains the official Salmonella Center, Calgary, Canada), Philip Hartman, Princeton University, and to Abraham Eisenstark, U. Missouri (see History of Collection, below). Thus, each of us had a complete collection.Keywords: Salmonella typhimurium; Archival storage; Viability; Aged bacteria

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“…Transduction as well as other recombinational processes are strongly affected by defectiveness of genes also involved in DNA repair following UV irradiation (CLARK 1965, EISENSTARK 1969, HORII and CLARK 1973, Resistance to TCi phages was used as a feature to be transduced. It was first necessary to investigate the spontaneous mutation rate a t 32 "C and 42 "C.…”

Section: T R a N S D U C T I O N E F F I C I E N C Ymentioning

confidence: 99%

Further studies on a temperature‐sensitive mutant of Escherichia coli with defective repair capacity

Morfiadakis

Geißler

1981

J of Basic Microbiology

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A temperature-sensitive mutant of E. coli, WG24, was studied with respect to its sensitivity to photodynamic action, its capacity to perform host controlled reactivation, and its sensitivity to transduction a t elevated temperatures. Mutant cells are much more sensitive than wild type cells to photodynamic action by thiopyronine and visible light a t elevated temperatures. As well defined rec mutants, WG24 cells are less able to reactivate UV irradiated I c phages a t elevated temperatures, while their ability to repair T1 phages is less impaired. Mutant cells cannot be transduced t o T6 resistance a t a detectable rate a t elevated temperature. It is concluded, therefore, that some rec gene carries a ts mutation in this mutant.

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Radiation-sensitive and recombinationless mutants of salmonella typhimurium

Cited by 38 publications

References 5 publications

Salmonella recD mutations increase recombination in a short sequence transduction assay

Salmonella recD mutations increase recombination in a short sequence transduction assay

The Immortal Salmonella typhimurium. (Amnesia among Resting Cells)

Further studies on a temperature‐sensitive mutant of Escherichia coli with defective repair capacity

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