title: Global transcriptional analysis of Methanosarcina mazei strain Gö1 under different nitrogen availabilities.
abstract: Certain archaeal species can fix molecular nitrogen under nitrogen limiting conditions although little is known about this process at either the genetic or molecular level. To address this on a genome-wide scale, transcriptional analysis was performed on the model methanogen Methanosarcina mazei strain Gö1 using DNA-microarrays. The genomic expression patterns for cells grown under nitrogen fixing conditions versus nitrogen sufficiency (10 mM ammonium) revealed that approximately 5% of all genes are differentially expressed. Besides a small set of genes previously known to be up-regulated under nitrogen limitation, 14 additional genes involved in nitrogen metabolism were identified plus 10 genes encoding potential transcriptional regulators, 13 genes involved in carbon metabolism, 3 genes in general stress response, 8 putative transporter genes, and an additional 21 genes with unknown function. Quantitative reverse transcriptase PCR experiments confirmed the differential expression of a subset of these genes. Promoter analysis revealed a palindromic DNA motif centered nearby the transcriptional start point for several genes up-regulated under nitrogen limitation. A bioinformatics study demonstrated the presence of this motif in the up-stream region of 52 genes genome-wide, the majority of which showed nitrogen dependent differential transcription. We therefore hypothesize that this DNA element is involved in nitrogen control in M. mazei where it may act as a binding site for a regulatory protein.
authors.affiliation: Institut für Allgemeine Mikrobiologie, Christian-Albrechts-Universität Kiel, Am Botanischen Garten 1-9, 24118, Kiel, Germany.
authors.forename: Katharina
authors.initials: K
authors.lastname: Veit
authors.forename: Claudia
authors.initials: C
authors.lastname: Ehlers
authors.forename: Armin
authors.initials: A
authors.lastname: Ehrenreich
authors.forename: Kirsty
authors.initials: K
authors.lastname: Salmon
authors.forename: Raymond
authors.initials: R
authors.lastname: Hovey
authors.forename: Robert P
authors.initials: RP
authors.lastname: Gunsalus
authors.forename: Uwe
authors.initials: U
authors.lastname: Deppenmeier
authors.forename: Ruth A
authors.initials: RA
authors.lastname: Schmitz
mesh_terms: D019843:Archaeal Proteins / Q000235:genetics*; D001483:Base Sequence; D001665:Binding Sites; D019295:Computational Biology; D020869:Gene Expression Profiling; D019848:Gene Expression Regulation, Archaeal; D017343:Genes, Plant / Q000502:physiology*; D017020:Methanosarcina / Q000235:genetics*; D008969:Molecular Sequence Data; D009584:Nitrogen / Q000378:metabolism*; D009586:Nitrogen Fixation / Q000235:genetics*; D020411:Oligonucleotide Array Sequence Analysis; D019642:RNA, Archaeal / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014158:Transcription, Genetic
chemical_list: D019843:Archaeal Proteins; D019642:RNA, Archaeal; D009584:Nitrogen