A GntR family transcriptional regulator (PigT) controls gluconate-mediated repression and defines a new, independent pathway for regulation of the tripyrrole antibiotic, prodigiosin, in Serratia.
Biosynthesis of the red, tripyrrole antibiotic prodigiosin (Pig) by Serratia sp. ATCC 39006 (39006) is controlled by a complex regulatory network involving an N-acyl homoserine lactone (N-AHL) quorum-sensing system, at least two separate two-component signal transduction systems and a multitude of other regulators. In this study, a new transcriptional activator, PigT, and a physiological cue (gluconate), which are involved in an independent pathway controlling Pig biosynthesis, have been characterized. PigT, a GntR homologue, activates transcription of the pigA-O biosynthetic operon in the absence of gluconate. However, addition of gluconate to the growth medium of 39006 repressed transcription of pigA-O, via a PigT-dependent mechanism, resulting in a decrease in Pig production. Finally, expression of the pigT transcript was shown to be maximal in exponential phase, preceding the onset of Pig production. This work expands our understanding of both the physiological and genetic factors that impinge on the biosynthesis of the secondary metabolite Pig in 39006.
Fineran
Peter C
PC
Department of Biochemistry, University of Cambridge, Cambridge CB2 1QW, UK.
Everson
Lee
L
Department of Biochemistry, University of Cambridge, Cambridge CB2 1QW, UK.
Slater
Holly
H
Department of Biochemistry, University of Cambridge, Cambridge CB2 1QW, UK.
Salmond
George P C
GPC
Department of Biochemistry, University of Cambridge, Cambridge CB2 1QW, UK.
D015107:4-Butyrolactone / Q000031:analogs & derivatives; D000900:Anti-Bacterial Agents / Q000096:biosynthesis*; D004268:DNA-Binding Proteins / Q000502:physiology*; D029968:Escherichia coli Proteins / Q000502:physiology*; D015964:Gene Expression Regulation, Bacterial; D005809:Genes, Regulator; D008969:Molecular Sequence Data; D011353:Prodigiosin / Q000096:biosynthesis*; D012097:Repressor Proteins / Q000502:physiology*; D012705:Serratia / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D015398:Signal Transduction; D014157:Transcription Factors / Q000502:physiology*; D014158:Transcription, Genetic
D000900:Anti-Bacterial Agents; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; C081598:GntR protein, E coli; D012097:Repressor Proteins; D014157:Transcription Factors; C088386:homoserine lactone; D011353:Prodigiosin; D015107:4-Butyrolactone