Synthesis of a Bacillus subtilis small, acid-soluble spore protein in Escherichia coli causes cell DNA to assume some characteristics of spore DNA.
Small, acid-soluble proteins (SASP) of the alpha/beta-type are associated with DNA in spores of Bacillus subtilis. Induction of synthesis of alpha/beta-type SASP in Escherichia coli resulted in rapid cessation of DNA synthesis, followed by a halt in RNA and then protein accumulation, although significant mRNA and protein synthesis continued. There was a significant loss in viability associated with SASP synthesis in E. coli: recA+ cells became extremely long filaments, whereas recA mutant cells became less filamentous. The nucleoids of cells with alpha/beta-type SASP were extremely condensed, as viewed in both light and electron microscopes, and immunoelectron microscopy showed that the alpha/beta-type SASP were associated with the cell DNA. Induction of alpha/beta-type SASP synthesis in E. coli increased the negative superhelical density of plasmid DNA by approximately 20%; UV irradiation of E. coli with alpha/beta-type SASP gave reduced yields of thymine dimers but significant amounts of the spore photoproduct. These changes in E. coli DNA topology and photochemistry due to alpha/beta-type SASP are similar to the effects of alpha/beta-type SASP on the DNA in Bacillus spores, further suggesting that alpha/beta-type SASP are a major factor determining DNA properties in bacterial spores.
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Department of Biochemistry, University of Connecticut Health Center, Farmington 06032.
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D001412:Bacillus subtilis / Q000235:genetics*; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D004269:DNA, Bacterial / Q000235:genetics; D004278:DNA, Superhelical / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics* / Q000254:growth & development / Q000528:radiation effects / Q000648:ultrastructure; D005838:Genotype; D007700:Kinetics; D008854:Microscopy, Electron; D008856:Microscopy, Fluorescence; D010957:Plasmids; D011994:Recombinant Proteins / Q000378:metabolism; D015183:Restriction Mapping; D012808:Sigma Factor; D013171:Spores, Bacterial / Q000502:physiology; D014157:Transcription Factors; D014466:Ultraviolet Rays
D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004278:DNA, Superhelical; D011994:Recombinant Proteins; D012808:Sigma Factor; D014157:Transcription Factors; C092468:spoIIR protein, Bacillus subtilis; C030069:spore-specific proteins, Bacillus