SOS-like induction in Bacillus subtilis: induction of the RecA protein analog and a damage-inducible operon by DNA damage in Rec+ and DNA repair-deficient strains

Journal Article · Fri Apr 01 00:00:00 EST 1988 · J. Bacteriol.; (United States)

OSTI ID:7252625

Lovett, Jr, C M; Love, P E; Yasbin, R E; Roberts, J W

We quantitated the induction of the Bacillus subtilis Rec protein (the analog of Escherichia coli RecA protein) and the B. subtilis din-22 operon (representative of a set of DNA damage-inducible operons in B. subtilis) following DNA damage in Rec+ and DNA repair-deficient strains. After exposure to mitomycin C or UV irradiation, each of four distinct rec (recA1, recB2, recE4, and recM13) mutations reduced to the same extent the rates of both Rec protein induction (determined by densitometric scanning of immunoblot transfers) and din-22 operon induction (determined by assaying beta-galactosidase activity in din-22::Tn917-lacZ fusion strains). The induction deficiencies in recA1 and recE4 strains were partially complemented by the E. coli RecA protein, which was expressed on a plasmid in B. subtilis; the E. coli RecA protein had no effect on either induction event in Rec+, recB2, or recM13 strains. These results suggest that (i) the expression of both the B. subtilis Rec protein and the din-22 operon share a common regulatory component, (ii) the recA1 and recE4 mutations affect the regulation and/or activity of the B. subtilis Rec protein, and (iii) an SOS regulatory system like the E. coli system is highly conserved in B. subtilis. We also showed that the basal level of B. subtilis Rec protein is about 4,500 molecules per cell and that maximum induction by DNA damage causes an approximately fivefold increase in the rate of Rec protein accumulation.

• Research Organization: Williams College, Williamstown, MA (USA)
• OSTI ID: 7252625
• Journal Information: J. Bacteriol.; (United States), Vol. 170:4
• Country of Publication: United States
• Language: English

Related Subjects

63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
BACILLUS SUBTILIS
DNA REPAIR
GENETIC RADIATION EFFECTS
MUTATIONS
RADIOINDUCTION
ENZYME INDUCTION
GENE RECOMBINATION
PLASMIDS
ULTRAVIOLET RADIATION
BACILLUS
BACTERIA
BIOLOGICAL EFFECTS
BIOLOGICAL RADIATION EFFECTS
BIOLOGICAL RECOVERY
BIOLOGICAL REPAIR
CELL CONSTITUENTS
ELECTROMAGNETIC RADIATION
GENE REGULATION
GENETIC EFFECTS
MICROORGANISMS
RADIATION EFFECTS
RADIATIONS
RECOVERY
REPAIR
560130* - Radiation Effects on Microorganisms