title: Transcriptional organization of the DNA region controlling expression of the K99 gene cluster.
abstract: The transcriptional organization of the K99 gene cluster was investigated in two ways. First, the DNA region, containing the transcriptional signals was analyzed using a transcription vector system with Escherichia coli galactokinase (GalK) as assayable marker and second, an in vitro transcription system was employed. A detailed analysis of the transcription signals revealed that a strong promoter PA and a moderate promoter PB are located upstream of fanA and fanB, respectively. No promoter activity was detected in the intercistronic region between fanB and fanC. Factor-dependent terminators of transcription were detected and are probably located in the intercistronic region between fanA and fanB (T1), and between fanB and fanC (T2). A third terminator (T3) was observed between fanC and fanD and has an efficiency of 90%. Analysis of the regulatory region in an in vitro transcription system confirmed the location of the respective transcription signals. A model for the transcriptional organization of the K99 cluster is presented. Indications were obtained that the trans-acting regulatory polypeptides FanA and FanB both function as anti-terminators. A model for the regulation of expression of the K99 gene cluster is postulated.
authors.affiliation: Department of Molecular Microbiology, Vrije Universiteit, Amsterdam, The Netherlands.
authors.forename: B
authors.initials: B
authors.lastname: Roosendaal
authors.forename: J
authors.initials: J
authors.lastname: Damoiseaux
authors.forename: W
authors.initials: W
authors.lastname: Jordi
authors.forename: F K
authors.initials: FK
authors.lastname: de Graaf
mesh_terms: D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics*; D005686:Galactokinase / Q000235:genetics*; D005786:Gene Expression Regulation; D005796:Genes; D005798:Genes, Bacterial; D005809:Genes, Regulator; D005816:Genetic Complementation Test; D005810:Multigene Family; D010957:Plasmids; D011401:Promoter Regions, Genetic; D015183:Restriction Mapping; D014158:Transcription, Genetic
chemical_list: D005686:Galactokinase