A plasmid-born Rap-Phr system regulates surfactin production, sporulation and genetic competence in the heterologous host, Bacillus subtilis OKB105.
According to the change of environment, soil-dwelling Bacillus species differentiate into distinct subpopulations, such as spores and competent cells. Rap-Phr systems have been found to be involved in this differentiation circuit by interacting with major regulatory proteins, such as Spo0A, ComA, and DegU. In this study, we report that the plasmid-born RapQ-PhrQ system found in Bacillus amyloliquefaciens B3 affects three regulatory pathways in the heterologous host Bacillus subtilis. Expression of rapQ in B. subtilis OKB105 strongly suppressed its sporulation efficiency, transformation efficiency, and surfactin production. Co-expression of phrQ or addition of synthesized PhrQ pentapeptide in vitro could compensate for the suppressive effects caused by rapQ. We also found that expression of rapQ decreased the transcriptional level of the sporulation-related gene spoIIE and surfactin synthesis-related gene srfA; meanwhile, the transcriptional levels of these genes could be rescued by co-expression of phrQ and in vitro addition of PhrQ pentapeptide. Electrophoretic mobility shift (EMSA) result also showed that RapQ could bind to ComA without interacting with ComA binding to DNA, and PhrQ pentapeptide antagonized RapQ activity in vitro. These results indicate that this new plasmid-born RapQ-PhrQ system controls sporulation, competent cell formation, and surfactin production in B. subtilis OKB105.
Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China.
Yang
Y
Yang
Hui-Jun
HJ
Wu
Ling
L
Lin
Qing-Qing
QQ
Zhu
Rainer
R
Borriss
Xue-Wen
XW
Gao
D001412:Bacillus subtilis / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D061269:DNA Transformation Competence; D015870:Gene Expression; D015964:Gene Expression Regulation, Bacterial; D055666:Lipopeptides / Q000096:biosynthesis* / Q000235:genetics; D010456:Peptides, Cyclic / Q000096:biosynthesis* / Q000235:genetics; D010957:Plasmids; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D013171:Spores, Bacterial / Q000254:growth & development
D001426:Bacterial Proteins; D055666:Lipopeptides; D010456:Peptides, Cyclic; D011994:Recombinant Proteins; C009365:surfactin peptide