title: Escherichia coli pfs transcription: regulation and proposed roles in autoinducer-2 synthesis and purine excretion.
abstract: Pfs expression is required for several metabolic pathways and limits the production of autoinducer-2, a molecule proposed to play a central role in interspecies quorum sensing. The present study reveals physiological conditions and promoter DNA elements that regulate Escherichia coli pfs transcription. Pfs transcription is shown to rely on both sigma 70 and sigma 38 (rpoS), and the latter is subject to induction that increases pfs expression. Transcription is maximal as the cells approach stationary phase, and this level can be increased by salt stress through induction of sigma 38-dependent expression. The pfs promoter is shown to contain both positive and negative elements, which can be used by both forms of RNA polymerase. The negative element is contained within the overlapping dgt promoter, which is involved in purine metabolism. Consideration of the physiological roles of sigma 38 and dgt leads to a model for how autoinducer production is controlled under changing physiological conditions.
authors.affiliation: Department of Chemistry and Biochemistry and The Molecular Biology Institute, University of California, Los Angeles, P.O. Box 951569, 90095, USA.
authors.forename: Youngbae
authors.initials: Y
authors.lastname: Kim
authors.forename: Chih M
authors.initials: CM
authors.lastname: Lew
authors.forename: Jay D
authors.initials: JD
authors.lastname: Gralla
mesh_terms: D001426:Bacterial Proteins / Q000378:metabolism; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics / Q000502:physiology*; D015964:Gene Expression Regulation, Bacterial; D006714:Homoserine / Q000031:analogs & derivatives* / Q000096:biosynthesis; D007783:Lactones; D009699:N-Glycosyl Hydrolases / Q000096:biosynthesis / Q000235:genetics* / Q000502:physiology*; D011401:Promoter Regions, Genetic; D011687:Purines / Q000378:metabolism*; D012329:RNA, Bacterial / Q000032:analysis / Q000235:genetics; D012333:RNA, Messenger / Q000032:analysis / Q000235:genetics; D012808:Sigma Factor / Q000378:metabolism; D014158:Transcription, Genetic
chemical_list: D001426:Bacterial Proteins; D007783:Lactones; C091088:N-octanoylhomoserine lactone; D011687:Purines; D012329:RNA, Bacterial; D012333:RNA, Messenger; D012808:Sigma Factor; C069567:sigma factor KatF protein, Bacteria; D006714:Homoserine; C081775:RNA polymerase sigma 70; D012321:DNA-Directed RNA Polymerases; D009699:N-Glycosyl Hydrolases; C019606:adenosylhomocysteine nucleosidase; C030985:purine