Transcriptional and translational control through the 5′‐leader region of the dmpR master regulatory gene of phenol metabolism. (25th June 2014)

• Record Type: Journal Article
• Authors: Madhushani, Anjana; del Peso‐Santos, Teresa; Moreno, Renata; Rojo, Fernando; Shingler, Victoria
• Is Part Of: Environmental microbiology. Volume 17:Number 1(2015:Jan.)
• Page Start: 119
• Page End: 133
• Publication Date: 2014-06-25
• Subjects: Microbial ecology -- Periodicals; Environmental Microbiology -- Periodicals; 579.17
• DOI: 10.1111/1462-2920.12511
• Languages: English
• ISSNs: 1462-2912

Abstract

<abstract abstract-type="main"> <title>Summary</title> <p>Expression of pathways for dissimilation of toxic aromatic compounds such as (methyl)phenols interfaces both stress‐response and carbon catabolite repression control cascades. In <italic>P</italic><italic>seudomonas putida</italic>, carbon catabolite repression is mediated by the protein Crc – a translational repressor that counteracts utilization of less‐preferred carbon sources as growth substrates until they are needed. In this work we dissect the regulatory role of the 5′‐leader region (5′‐LR) of the <italic>dmpR</italic> gene that encodes the master regulator of (methyl)phenol catabolism. Using deletion and substitution mutants combined with artificial manipulations of Crc availability in <italic>P</italic><italic>. putida</italic>, we present evidence that a DNA motif within the 5′‐leader region is critical for inhibition of the output from the Pr promoter that drives transcription of <italic>dmpR</italic>, while the RNA chaperone Hfq facilitates Crc‐mediated translation repression through the 5′‐leader region of the <italic>dmpR</italic> mRNA. The results are discussed in the light of a model in which Hfq assists Crc to target a sequence within a loop formed by secondary structure of the 5′‐LR mRNA. Our results support the idea that Crc functions as a global translational inhibitor to co‐ordinate hierarchical carbon utilization in Pseudomonads.</p> </abstract>