Molecular switch controlling expression of the mannose-specific adhesin, Msa, in Lactobacillus plantarum

Research output: Contribution to journalArticle

Abstract

Some lactic acid bacteria, especially Lactobacillus spp., possess adhesive properties enabling colonization of the human gastrointestinal tract. Two probiotic Lactobacillus plantarum strains, WCSF1 and 299v, display highly different mannose-specific adhesion, with L. plantarum 299v being superior to L. plantarum WCFS1 based on a yeast agglutination assay. A straightforward correlation between the mannose adhesion capacity and domain composition of the mannose-specific adhesin (Msa) in the two strains has not been demonstrated previously. In this study, we analyzed the promoter regions upstream of the msa gene encoding a mannose-specific adhesin in these two strains. The promoter region was mapped by primer extension and DNA sequence analysis, and only a single nucleotide change was identified between the two strains. However, Northern blot analysis showed a stronger msa transcript band in 299v than in WCFS1 correlating with the different adhesion capacities. During the establishment of a high-throughput yeast agglutination assay, we isolated variants of WCFS1 that displayed a very strong mannose-specific adhesion phenotype. The region upstream of the msa gene in these variants showed an inversion of a 104-bp fragment located between two perfectly inverted repeats present in the untranslated leader region. The inversion disrupts a strong hairpin structure that otherwise most likely would terminate the msa transcript. In addition, the ribosome binding site upstream of the msa gene, which is also masked within this hairpin structure, becomes accessible upon inversion, thereby increasing the frequency of translation initiation in the variant strains. Furthermore, Northern blot analysis showed a higher abundance of the msa transcript in the variants than in the wild type, correlating with a strong-Msa phenotype.

Details

Authors
  • Bjørn Holst
  • Jacob Glenting
  • Kim Holmstrøm
  • Hans Israelsen
  • Astrid Vrang
  • Martin Antonsson
  • Siv Ahrné
  • Søren M. Madsen
Organisations
External organisations
  • Bioneer A/S
  • ProViva AB
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Microbiology in the medical area
  • Food Engineering

Keywords

  • Lactobacillus plantarum, Mannose-specific adhesin, Probiotics, Site-specific DNA inversion systems
Original languageEnglish
Article numbere02954-18
JournalApplied and Environmental Microbiology
Volume85
Issue number10
Publication statusPublished - 2019
Publication categoryResearch
Peer-reviewedYes