title: Small, Acid-Soluble Spore Proteins of the alpha/beta Type Do Not Protect the DNA in Bacillus subtilis Spores against Base Alkylation
abstract: Ethyl methanesulfonate (EMS) killed wild-type Bacillus subtilis spores as rapidly as spores lacking small, acid-soluble proteins (SASP) of the alpha/beta type (alpha-beta- spores), and 20% of the survivors had obvious mutations. A recA mutation increased the EMS sensitivity of wild-type and alpha-beta- spores similarly but reduced their mutagenesis; EMS treatment of dormant spores also resulted in the induction of RecA synthesis during spore germination. EMS generated similar levels of alkylated bases in wild-type and alpha-beta- spore DNAs, in purified DNA, or in DNA saturated with alpha/beta-type SASP. Ethylene oxide (EtO) also generated similar levels of base alkylation in wild-type and alpha-beta- spore DNAs. These data indicate that EMS and EtO kill spores at least in part by DNA damage but that alpha/beta-type SASP, which protect DNA against many types of damage, do not protect spore DNA from base alkylation.
authors.affiliation: Department of Biochemistry, University of Connecticut Health Center, Farmington, Connecticut 06032.
authors.initials: B
authors.lastname: Setlow
authors.initials: KJ
authors.lastname: Tautvydas
authors.initials: P
authors.lastname: Setlow