The ClpXP protease is responsible for the degradation of the Epsilon antidote to the Zeta toxin of the streptococcal pSM19035 plasmid.
Most bacterial genomes contain different types of toxin-antitoxin (TA) systems. The ω-ε-ζ proteinaceous type II TA cassette from the streptococcal pSM19035 plasmid is a member of the ε/ζ family, which is commonly found in multiresistance plasmids and chromosomes of various human pathogens. Regulation of type II TA systems relies on the proteolysis of antitoxin proteins. Under normal conditions, the Epsilon antidote neutralizes the Zeta toxin through the formation of a tight complex. In this study, we show, using both in vivo and in vitro analyses, that the ClpXP protease is responsible for Epsilon antitoxin degradation. Using in vivo studies, we examined the stability of the plasmids with active or inactive ω-ε-ζ TA cassettes in B. subtilis mutants that were defective for different proteases. Using in vitro assays, the degradation of purified His6-Epsilon by the His6-LonBs, ClpPBs, and ClpXBs proteases from B. subtilis was analyzed. Additionally, we showed that purified Zeta toxin protects the Epsilon protein from rapid ClpXP-catalyzed degradation.
From the Institute of Biochemistry and Biophysics, Polish Academy of Sciences, 02-106 Warsaw, Poland.
Iwona
I
Brzozowska
Urszula
U
Zielenkiewicz
D001412:Bacillus subtilis / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D001427:Bacterial Toxins / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D002384:Catalysis; D002853:Chromatography, Liquid; D004247:DNA / Q000737:chemistry; D049071:Endopeptidase Clp / Q000235:genetics / Q000378:metabolism*; D004926:Escherichia coli / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism*; D013058:Mass Spectrometry; D009154:Mutation; D010957:Plasmids / Q000378:metabolism; D013045:Species Specificity; D013297:Streptococcus pyogenes / Q000378:metabolism*
D001426:Bacterial Proteins; D001427:Bacterial Toxins; D029968:Escherichia coli Proteins; D004247:DNA; C483573:ClpXP protease, E coli; C588334:ClpXP protease, Streptococcus; D049071:Endopeptidase Clp
ATP-dependent Protease; Microbiology; Protease; Protein Degradation; Streptococcus pyogenes