Genes involved in SkfA killing factor production protect a Bacillus subtilis lipase against proteolysis.
Small lipases of Bacillus species, such as LipA from Bacillus subtilis, have a high potential for industrial applications. Recent studies showed that deletion of six AT-rich islands from the B. subtilis genome results in reduced amounts of extracellular LipA. Here we demonstrate that the reduced LipA levels are due to the absence of four genes, skfABCD, located in the prophage 1 region. Intact skfABCD genes are required not only for LipA production at wild-type levels by B. subtilis 168 but also under conditions of LipA overproduction. Notably, SkfA has bactericidal activity and, probably, requires the SkfB to SkfD proteins for its production. The present results show that LipA is more prone to proteolytic degradation in the absence of SkfA and that high-level LipA production can be improved significantly by employing multiple protease-deficient B. subtilis strains. In conclusion, our findings imply that SkfA protects LipA, directly or indirectly, against proteolytic degradation. Conceivably, SkfA could act as a modulator in LipA folding or as a protease inhibitor.
Westers
Helga
H
Department of Pharmaceutical Biology, University of Groningen, Hanzeplein 1, P.O. Box 30 001, 9700 RB Groningen, the Netherlands.
Braun
Peter G
PG
Westers
Lidia
L
Antelmann
Haike
H
Hecker
Michael
M
Jongbloed
Jan D H
JD
Yoshikawa
Hirofumi
H
Tanaka
Teruo
T
van Dijl
Jan Maarten
JM
Quax
Wim J
WJ
D001412:Bacillus subtilis / Q000201:enzymology* / Q000235:genetics* / Q000254:growth & development / Q000821:virology; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism*; D003470:Culture Media; D015964:Gene Expression Regulation, Bacterial; D008049:Lipase / Q000378:metabolism*; D005810:Multigene Family; D020411:Oligonucleotide Array Sequence Analysis / Q000379:methods; D020543:Proteome; D014158:Transcription, Genetic
D001426:Bacterial Proteins; D003470:Culture Media; C079999:LipA protein, Bacteria; D020543:Proteome; D008049:Lipase