Escherichia coli xonA (sbcB) mutants enhance illegitimate recombination

Journal Article · Mon Apr 01 04:00:00 EST 1991 · Genetics; (USA)

OSTI ID:5639320

Allgood, N D; Silhavy, T J ^[1]

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1. Princeton Univ., NJ (USA)

Mutations of Escherichia coli K-12 were isolated that increase the frequency of deletion formation. Three of these mutations map to the gene sbcB at 43.5 min on the E. coli chromosome. Two types of mutations at sbcB have been previously defined: sbcB-type that suppress both the UV sensitivity and recombination deficiency of recBC mutants, and xonA-type that suppress only the UV sensitivity. Both types are defective for production of exonuclease I activity. The mutations isolated here were similar to xonA alleles of sbcB because they suppressed the UV sensitivity of recBC mutants but did not restore recombination proficiency. Indeed, two previously characterized xonA alleles were shown to increase the frequency of deletion formation, although an sbcB allele did not. This result demonstrates that loss of exonuclease I activity is not sufficient to confer a high deletion phenotype, rather, the product of the sbcB gene possesses some other function that is important for deletion formation. Because deletion formation in this system is recA independent and does not require extensive DNA homology, these mutations affect a pathway of illegitimate recombination.

• OSTI ID: 5639320
• Journal Information: Genetics; (USA), Journal Name: Genetics; (USA) Vol. 127:4; ISSN 0016-6731; ISSN GENTA
• Country of Publication: United States
• Language: English

Related Subjects

560130* -- Radiation Effects on Microorganisms
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
BACTERIA
BIOLOGICAL EFFECTS
BIOLOGICAL PATHWAYS
BIOLOGICAL RADIATION EFFECTS
CELL CONSTITUENTS
ELECTROMAGNETIC RADIATION
ENZYME ACTIVITY
ENZYMES
ESCHERICHIA COLI
ESTERASES
GENE MUTATIONS
GENE OPERONS
GENE RECOMBINATION
GENETIC EFFECTS
GENETIC MAPPING
GENETIC RADIATION EFFECTS
HYDROLASES
MAPPING
MICROORGANISMS
MUTATION FREQUENCY
MUTATIONS
NUCLEASES
PHENOTYPE
PHOSPHODIESTERASES
PLASMIDS
RADIATION EFFECTS
RADIATIONS
ULTRAVIOLET RADIATION