title: Modulation of transcription and characterization of the promoter organization of the autotransporter adhesin heptosyltransferase and the autotransporter adhesin AIDA-I.
abstract: In Gram-negative bacteria, autotransporter proteins constitute the largest family of secreted proteins, and exhibit many different functions. In recent years, research has largely focused on mechanisms of autotransporter protein translocation, where several alternative models are still being discussed. In contrast, the biogenesis of only a few autotransporters has been studied and, likewise, regulation of expression has received only very limited attention. The glycosylated autotransporter adhesin involved in diffuse adherence (AIDA)-I system consists of the aah gene, encoding a specific autotransporter adhesin heptosyltransferase (AAH), and the aidA gene, encoding the autotransporter protein (AIDA-I). In this study, we investigated the promoter organization and transcription of these two genes using reporter plasmids carrying lacZ transcriptional fusions. The two genes, aah and aidA, are transcribed as a bicistronic message. However, aidA is additionally transcribed from its own promoter. There are two distinct start sites for each of the two genes. Interestingly, transcription of both genes is enhanced in hns and rfaH mutant backgrounds. Furthermore, we addressed the influence of environmental factors and different genetic backgrounds of Escherichia coli K-12 strains on transcription activity. We found that transcription varied considerably in different E. coli K-12 laboratory strains and under different growth conditions.
authors.affiliation: Institut für Infektiologie, Zentrum für Molekularbiologie der Entzündung (ZMBE), Westfälische Wilhelms-Universität Münster, D-48149 Münster, Germany.
authors.forename: Inga
authors.initials: I
authors.lastname: Benz
authors.affiliation: Institut für Infektiologie, Zentrum für Molekularbiologie der Entzündung (ZMBE), Westfälische Wilhelms-Universität Münster, D-48149 Münster, Germany.
authors.forename: Tessa
authors.initials: T
authors.lastname: van Alen
authors.affiliation: Institut für Infektiologie, Zentrum für Molekularbiologie der Entzündung (ZMBE), Westfälische Wilhelms-Universität Münster, D-48149 Münster, Germany.
authors.forename: Julia
authors.initials: J
authors.lastname: Bolte
authors.affiliation: Institut für Infektiologie, Zentrum für Molekularbiologie der Entzündung (ZMBE), Westfälische Wilhelms-Universität Münster, D-48149 Münster, Germany.
authors.forename: Mirka E
authors.initials: ME
authors.lastname: Wörmann
authors.affiliation: Institut für Infektiologie, Zentrum für Molekularbiologie der Entzündung (ZMBE), Westfälische Wilhelms-Universität Münster, D-48149 Münster, Germany.
authors.forename: M Alexander
authors.initials: MA
authors.lastname: Schmidt
mesh_terms: D018830:Adhesins, Escherichia coli / Q000235:genetics* / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000235:genetics* / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D016695:Glycosyltransferases / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D012329:RNA, Bacterial / Q000235:genetics; D014158:Transcription, Genetic
chemical_list: C075559:AIDA-I protein, E coli; D018830:Adhesins, Escherichia coli; D029968:Escherichia coli Proteins; D012329:RNA, Bacterial; D016695:Glycosyltransferases; C433803:autotransporter-adhesin-heptosyltransferase, E coli