Characterization of the transcriptional regulation of the tarIJKL locus involved in ribitol-containing wall teichoic acid biosynthesis in Lactobacillus plantarum

Abstract

Lactobacillus plantarum strains produce either glycerol (Gro)-or ribitol (Rbo)-backbone wall teichoic acid (WTA) (Gro-WTA and Rbo-WTA, respectively). The strain WCFS1 has been shown to be able to activate the tarIJKL locus involved in Rbo-WTA synthesis when the tagD1F1F2 locus for Gro-WTA synthesis was mutated, resulting in switching of the native Gro-WTA into Rbo-WTA. Here, we identify a regulator involved in the WTA backbone alditol switching and activation of the tarIJKL locus. Promoter reporter assays of the tarI promoter (P tar ) demonstrated its activity in the Rbo-WTA-producing mutant derivative (DtagF1-2) but not in the parental strain WCFS1. An electrophoresis mobility shift assay using a P tar nucleotide fragment showed that this fragment bound to P tar -binding protein(s) in a cell-free extract of WCFS1. Three proteins were subsequently isolated using P tar bound to magnetic beads. These proteins were isolated efficiently from the lysate of WCFS1 but not from the lysate of its DtagF1-2 derivative, and were identified as redox-sensitive transcription regulator (Lp_0725), catabolite control protein A (Lp_2256) and TetR family transcriptional regulator (Lp_1153). The role of these proteins in P tar regulation was investigated by knockout mutagenesis, showing that the Dlp_1153 mutant expressed the tarI gene at a significantly higher level, supporting its role as a repressor of the tarIJKL locus. Notably, the Dlp_1153 mutation also led to reduced expression of the tagF1 gene. These results show that Lp_1153 is a regulatory factor that plays a role in WTA alditol switching in Lb. plantarum WCFS1 and we propose to rename this gene/protein wasR/WasR, for WTA alditol switch regulator.

Genome Sequence of Oenococcus oeni UNQOe19, the First Fully Assembled Genome Sequence of a Patagonian Psychrotrophic Oenological Strain

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Streptococcus salivarius MS-oral-D6 promotes gingival re-epithelialization in vitro through a secreted serine protease

“…Ready-to-use Coomassie protein stain InstantBlue (Expedeon, Cambridgeshire, UK) was used to visualize the proteins on gel. In-gel trypsin digestion followed by liquid-chromatography tadem mass spectrometry (LC-MS/MS) was performed as previously described 70 . The protein band (>180 kDa) was excised from the gel and transferred to a low binding protein microcentrifuge tube.…”

The Copper Homeostasis Transcription Factor CopR Is Involved in H2O2 Stress in Lactobacillus plantarum CAUH2

“…In L. reuteri , the PocR-like TF controls the expression of its neighboring loci that harbors the genes for glycerol utilization and vitamin B 12 synthesis ( Santos et al, 2011 ). A TerR-like TF ( lp_1153 ) functions as a repressor of the tarIJKL locus involved in teichoic acid synthesis in L. plantarum WCFS1 ( Tomita et al, 2015 ). In addition, TF Ldb0677 has been identified to involve in acid tolerance, which was predicted to regulate 22 target genes by bacterial one-hybrid method in L. bulgaricus CAUH1 ( Zhai et al, 2014 ).…”