title: Expression of the Oligopeptide Permease Operon of Moraxella catarrhalis Is Regulated by Temperature and Nutrient Availability.
abstract: Moraxella catarrhalis causes otitis media in children and exacerbations of chronic obstructive pulmonary disease in adults. Together, these two conditions contribute to enormous morbidity and mortality worldwide. The oligopeptide permease (opp) ABC transport system is a nutritional virulence factor important for the utilization of peptides. The substrate binding protein OppA, which binds peptides for uptake, is a potential vaccine antigen, but little was known about the regulation of gene expression. The five opp genes oppB, oppC, oppD, oppF, and oppA are in the same open reading frame. Sequence analysis predicted two promoters, one located upstream of oppB and one within the intergenic region between oppF and oppA. We have characterized the gene cluster as an operon with two functional promoters and show that cold shock at 26°C for ≤ 0.5 h and the presence of a peptide substrate increase gene transcript levels. Additionally, the putative promoter upstream of oppA contributes to the transcription of oppA but is not influenced by the same environmental cues as the promoter upstream of oppB. We conclude that temperature and nutrient availability contribute to the regulation of the Opp system, which is an important nutritional virulence factor in M. catarrhalis.
authors.affiliation: Department of Microbiology and Immunology, University at Buffalo, The State University of New York, Buffalo, New York, USA Clinical and Translational Research Center, University at Buffalo, The State University of New York, Buffalo, New York, USA.
authors.forename: Megan M
authors.initials: MM
authors.lastname: Jones
authors.affiliation: Department of Microbiology and Immunology, University at Buffalo, The State University of New York, Buffalo, New York, USA Clinical and Translational Research Center, University at Buffalo, The State University of New York, Buffalo, New York, USA Division of Infectious Diseases, Department of Medicine, University at Buffalo, The State University of New York, Buffalo, New York, USA murphyt@buffalo.edu.
authors.forename: Timothy F
authors.initials: TF
authors.lastname: Murphy
mesh_terms: D001426:Bacterial Proteins / Q000096:biosynthesis*; D002352:Carrier Proteins / Q000096:biosynthesis*; D018929:Cell Culture Techniques / Q000379:methods; D015964:Gene Expression Regulation, Bacterial / Q000502:physiology*; D008074:Lipoproteins / Q000096:biosynthesis*; D001936:Moraxella catarrhalis / Q000201:enzymology* / Q000235:genetics* / Q000254:growth & development; D009876:Operon; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013696:Temperature
chemical_list: D001426:Bacterial Proteins; D002352:Carrier Proteins; D008074:Lipoproteins; C046506:oligopeptide-binding protein, bacteria