Cloning, deletion, and characterization of PadR, the transcriptional repressor of the phenolic acid decarboxylase-encoding padA gene of Lactobacillus plantarum.
Lactobacillus plantarum displays a substrate-inducible padA gene encoding a phenolic acid decarboxylase enzyme (PadA) that is considered a specific chemical stress response to the inducing substrate. The putative regulator of padA was located in the padA locus based on its 52% identity with PadR, the padA gene transcriptional regulator of Pediococcus pentosaceus (L. Barthelmebs, B. Lecomte, C. Diviès, and J.-F. Cavin, J. Bacteriol. 182:6724-6731, 2000). Deletion of the L. plantarum padR gene clearly demonstrates that the protein it encodes is the transcriptional repressor of divergently oriented padA. The padR gene is cotranscribed with a downstream open reading frame (ORF1), the product of which may belong to a group of universal stress proteins (Usp). The padR deletion mutant overexpressed padA constitutively, and the padA promoter appears to be tightly regulated in this bacterium. Gel mobility shift assays using the padA gene promoter region and purified PadR expressed in Escherichia coli indicated that operator DNA binding by PadR was not eliminated by addition of p-coumarate. Gel mobility shift assays using partially purified extracts of native PadR protein from both phenolic acid-induced and noninduced L. plantarum cells demonstrate that inactivation of PadR by phenolic acids requires the integrity of L. plantarum and mediation by a specific protein absent in E. coli.
Gury
Jérôme
J
Laboratoire de Microbiologie UMR UB/INRA 1232, ENSBANA, Université de Bourgogne, 21000 Dijon, France.
Barthelmebs
Lise
L
Tran
Ngoc Phuong
NP
Diviès
Charles
C
Cavin
Jean-François
JF
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D001665:Binding Sites / Q000235:genetics; D002262:Carboxy-Lyases / Q000235:genetics*; D003001:Cloning, Molecular; D003373:Coumaric Acids / Q000494:pharmacology; D017931:DNA Primers / Q000235:genetics; D004269:DNA, Bacterial / Q000235:genetics / Q000378:metabolism; D017353:Gene Deletion; D005798:Genes, Bacterial; D007778:Lactobacillus / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism*; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D011401:Promoter Regions, Genetic; D011422:Propionates; D012097:Repressor Proteins / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism; D017386:Sequence Homology, Amino Acid
D001426:Bacterial Proteins; D003373:Coumaric Acids; D017931:DNA Primers; D004269:DNA, Bacterial; D011422:Propionates; D012097:Repressor Proteins; D002262:Carboxy-Lyases; C417714:phenolic acid decarboxylase; C495469:p-coumaric acid