Negative Regulation of Violacein Biosynthesis inChromobacterium violaceum.
InChromobacteium violaceum, the purple pigment violacein is under positive regulation by theN-acylhomoserine lactone CviI/R quorum sensing system and negative regulation by an uncharacterized putative repressor. In this study we report that the biosynthesis of violacein is negatively controlled by a novel repressor protein, VioS. The violacein operon is regulated negatively by VioS and positively by the CviI/R system in bothC. violaceumand in a heterologousEscherichia coligenetic background. VioS does not regulate the CviI/R system and apart from violacein, VioS, and quorum sensing regulate other phenotypes antagonistically. Quorum sensing regulated phenotypes inC. violaceumare therefore further regulated providing an additional level of control.
International Centre for Genetic Engineering and Biotechnology Trieste, Italy.
Giulia
G
Devescovi
Laboratory for Molecular Microbiology, Institute of Molecular Genetics and Genetic Engineering, University of Belgrade Belgrade, Serbia.
Milan
M
Kojic
Consiglio Nazionale delle Ricerche, Istituto di Cristallografia, U.O.S di Trieste Trieste, Italy.
Sonia
S
Covaceuszach
Centre for Biomolecular Sciences, School of Life Sciences, University of Nottingham Nottingham, UK.
Miguel
M
Cámara
Centre for Biomolecular Sciences, School of Life Sciences, University of Nottingham Nottingham, UK.
Paul
P
Williams
International Centre for Genetic Engineering and Biotechnology Trieste, Italy.
Iris
I
Bertani
International Centre for Genetic Engineering and Biotechnology Trieste, Italy.
Sujatha
S
Subramoni
International Centre for Genetic Engineering and Biotechnology Trieste, Italy.
Vittorio
V
Venturi
Chromobacterium violaceum; CviI/R quorum sensing; VioS; chitinase activity; protease activity; regulation; violacein