title: The zinc-responsive regulon of Neisseria meningitidis comprises 17 genes under control of a Zur element.
abstract: Zinc is a bivalent cation essential for bacterial growth and metabolism. The human pathogen Neisseria meningitidis expresses a homologue of the Zinc uptake regulator Zur, which has been postulated to repress the putative zinc uptake protein ZnuD. In this study, we elucidated the transcriptome of meningococci in response to zinc by microarrays and quantitative real-time PCR (qRT-PCR). We identified 15 genes that were repressed and two genes that were activated upon zinc addition. All transcription units (genes and operons) harbored a putative Zur binding motif in their promoter regions. A meningococcal Zur binding consensus motif (Zur box) was deduced in silico, which harbors a conserved central palindrome consisting of hexameric inverted repeats separated by three nucleotides (TGTTATDNHATAACA). In vitro binding of recombinant meningococcal Zur to this Zur box was shown for the first time using electrophoretic mobility shift assays. Zur binding to DNA depended specifically on the presence of zinc and was sensitive to mutations in the palindromic sequence. The Zur regulon among genes of unknown function comprised genes involved in zinc uptake, tRNA modification, and ribosomal assembly. In summary, this is the first study of the transcriptional response to zinc in meningococci.
authors.affiliation: University of Würzburg, Institute for Hygiene and Microbiology, Würzburg, Germany.
authors.forename: Marie-Christin
authors.initials: MC
authors.lastname: Pawlik
authors.forename: Kerstin
authors.initials: K
authors.lastname: Hubert
authors.forename: Biju
authors.initials: B
authors.lastname: Joseph
authors.forename: Heike
authors.initials: H
authors.lastname: Claus
authors.forename: Christoph
authors.initials: C
authors.lastname: Schoen
authors.forename: Ulrich
authors.initials: U
authors.lastname: Vogel
mesh_terms: D001665:Binding Sites; D019295:Computational Biology; D024202:Electrophoretic Mobility Shift Assay; D015964:Gene Expression Regulation, Bacterial; D046228:Microarray Analysis; D009345:Neisseria meningitidis / Q000235:genetics* / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D060888:Real-Time Polymerase Chain Reaction; D018085:Regulon; D017422:Sequence Analysis, DNA; D014157:Transcription Factors / Q000378:metabolism; D059467:Transcriptome; D015032:Zinc / Q000378:metabolism*
chemical_list: D014157:Transcription Factors; D015032:Zinc