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

摘要: 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 import catabolism in marine Roseobacter species Ruegeria pomeroyi identified three transcriptional regulators involved these processes: GabR/MocR-type repressor EnuR, feast famine-type regulator AsnC two-component system NtrYX. The corresponding genes widely associated with uptake catabolic gene clusters (enuR, asnC), microorganisms predicted to consume ectoines (ntrYX). EnuR contains a covalently bound pyridoxal-5'-phosphate co-factor chemistry underlying functioning MocR/GabR-type typically requires system-specific low molecular mass effector molecule. Through ligand binding studies purified we N-(alpha)-L-acetyl-2,4-diaminobutyric acid L-2,4-diaminobutyric inducers that generated through catabolism. AsnC/Lrp-type proteins wrap DNA into nucleosome-like structures, found asnC was essential use nutrients. Furthermore, discovered transposon mutagenesis NtrYX is required their Database searches suggest our findings important ramifications an understanding biology most consumers ectoines.