5 years ago

Transcriptional regulation of ectoine catabolism in response to multiple metabolic and environmental cues

Erhard Bremer, Johann Heider, Jeroen S. Dickschat, Ramona Riclea, Tamara Hoffmann, Tobias Bönig, Sven-Andreas Freibert, Lucas Hermann, Annina Schulz
Ectoine and hydroxyectoine are effective microbial osmostress protectants, but can also serve as versatile nutrients for bacteria. We have studied the genetic regulation of ectoine and hydroxyectoine import and catabolism in the marine Roseobacter species Ruegeria pomeroyi and identified three transcriptional regulators involved in these processes: the GabR/MocR-type repressor EnuR, the feast and famine-type regulator AsnC, and the two-component system NtrYX. The corresponding genes are widely associated with ectoine and hydroxyectoine uptake and catabolic gene clusters (enuR, asnC), and with microorganisms predicted to consume ectoines (ntrYX). EnuR contains a covalently bound pyridoxal-5'-phosphate (PLP) as a co-factor and the chemistry underlying the functioning of MocR/GabR-type regulators typically requires a system-specific low molecular mass effector molecule. Through ligand binding studies with purified EnuR, we identified N-(alpha)-L-acetyl-2,4-diaminobutyric acid and L-2,4-diaminobutyric acid as inducers for EnuR that are generated through ectoine catabolism. AsnC/Lrp-type proteins can wrap DNA into nucleosome-like structures, and we found that the asnC gene was essential for use of ectoines as nutrients. Furthermore, we discovered through transposon mutagenesis that the NtrYX two-component system is required for their catabolism. Database searches suggests that our findings have important ramifications for an understanding of the molecular biology of most microbial consumers of ectoines. This article is protected by copyright. All rights reserved.

Publisher URL: http://onlinelibrary.wiley.com/resolve/doi

DOI: 10.1111/1462-2920.13924

You might also like
Discover & Discuss Important Research

Keeping up-to-date with research can feel impossible, with papers being published faster than you'll ever be able to read them. That's where Researcher comes in: we're simplifying discovery and making important discussions happen. With over 19,000 sources, including peer-reviewed journals, preprints, blogs, universities, podcasts and Live events across 10 research areas, you'll never miss what's important to you. It's like social media, but better. Oh, and we should mention - it's free.

  • Download from Google Play
  • Download from App Store
  • Download from AppInChina

Researcher displays publicly available abstracts and doesn’t host any full article content. If the content is open access, we will direct clicks from the abstracts to the publisher website and display the PDF copy on our platform. Clicks to view the full text will be directed to the publisher website, where only users with subscriptions or access through their institution are able to view the full article.