title: An upstream sequence element required for NucC-dependent expression of the Serratia marcescens extracellular nuclease.
abstract: The Serratia marcescens extracellular nuclease gene, nucA, is positively regulated by the product of the nucC gene. In this study, the upstream region required for NucC-dependent nuclease expression was defined by using fusions to the gene encoding chloramphenicol acetyltransferase (cat). This sequence includes an element of hyphenated dyad symmetry identified previously as the binding site for the P2 Ogr family of activators. Footprint analysis confirmed that members of this family of activator proteins bind to this site, protecting a region between -76 and -59 relative to the start of transcription. The activator binding site in the nucA promoter lies one turn of the helix upstream from the corresponding sites in the P2 and P4 late promoters. The effects of deletions between the downstream end of the activator binding site and the putative -35 region are consistent with a strict helical phasing requirement for activation.
authors.affiliation: Department of Microbiology and Immunology, Virginia Commonwealth University, Richmond, Virginia 23298-0678, USA.
authors.forename: R H
authors.initials: RH
authors.lastname: Winslow
authors.forename: B
authors.initials: B
authors.lastname: Julien
authors.forename: R
authors.initials: R
authors.lastname: Calendar
authors.forename: G E
authors.initials: GE
authors.lastname: Christie
mesh_terms: D001483:Base Sequence; D004269:DNA, Bacterial; D004706:Endodeoxyribonucleases / Q000235:genetics*; D004722:Endoribonucleases / Q000235:genetics*; D015964:Gene Expression Regulation, Bacterial; D015971:Gene Expression Regulation, Enzymologic; D008969:Molecular Sequence Data; D012045:Regulatory Sequences, Nucleic Acid; D012706:Serratia marcescens / Q000201:enzymology* / Q000235:genetics; D014157:Transcription Factors / Q000378:metabolism
chemical_list: D004269:DNA, Bacterial; D014157:Transcription Factors; D004706:Endodeoxyribonucleases; D004722:Endoribonucleases; C021835:Serratia marcescens nuclease