title: Transcriptional and translational control through the 5'-leader region of the dmpR master regulatory gene of phenol metabolism.
abstract: Expression of pathways for dissimilation of toxic aromatic compounds such as (methyl)phenols interfaces both stress-response and carbon catabolite repression control cascades. In Pseudomonas putida, 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 dmpR gene that encodes the master regulator of (methyl)phenol catabolism. Using deletion and substitution mutants combined with artificial manipulations of Crc availability in P. putida, 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 dmpR, while the RNA chaperone Hfq facilitates Crc-mediated translation repression through the 5'-leader region of the dmpR 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.
authors.affiliation: Department of Molecular Biology, Umeå University, Umeå, SE 90187, Sweden.
authors.forename: Anjana
authors.initials: A
authors.lastname: Madhushani
authors.forename: Teresa
authors.initials: T
authors.lastname: Del Peso-Santos
authors.forename: Renata
authors.initials: R
authors.lastname: Moreno
authors.forename: Fernando
authors.initials: F
authors.lastname: Rojo
authors.forename: Victoria
authors.initials: V
authors.lastname: Shingler
mesh_terms: D020121:5' Untranslated Regions; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D005809:Genes, Regulator; D035001:Host Factor 1 Protein / Q000378:metabolism; D011401:Promoter Regions, Genetic; D014176:Protein Biosynthesis; D016958:Pseudomonas putida / Q000235:genetics* / Q000378:metabolism; D012329:RNA, Bacterial / Q000378:metabolism; D038621:Regulatory Sequences, Ribonucleic Acid; D012097:Repressor Proteins / Q000378:metabolism; D015534:Trans-Activators / Q000235:genetics*; D014158:Transcription, Genetic
chemical_list: D020121:5' Untranslated Regions; D001426:Bacterial Proteins; C080133:DmpR protein, Pseudomonas; D035001:Host Factor 1 Protein; D012329:RNA, Bacterial; D038621:Regulatory Sequences, Ribonucleic Acid; D012097:Repressor Proteins; D015534:Trans-Activators; C101896:crc protein, Pseudomonas