title: Characterization of the glnB gene product of Nostoc punctiforme strain ATCC 29133: glnB or the PII protein may be essential.
abstract: Bacterial PII proteins, encoded by glnB genes, are central signalling molecules in nitrogen regulatory pathways and are modulated by post-translational modification in response to the cellular nitrogen status. The glnB gene was cloned from the filamentous heterocyst-forming cyanobacterium Nostoc punctiforme strain ATCC 29133 (PCC 73102) by heterologous hybridization to a Synechococcus sp. strain PCC 7942 gene fragment. Expression of the cloned gene was verified by hybridization to N. punctiforme total RNA and a single cross-reactive polypeptide was observed in immunoblots of N. punctiforme extracts probed with anti-Synechococcus 7942 PII antiserum. Modification of the purified N. punctiforme PII protein by a Synechococcus 7942 PII kinase was observed, but modified forms of PII were not detected in extracts of N. punctiforme from a variety of incubation conditions. The N. punctiforme glnB gene could not be disrupted by targeted gene replacement unless a second copy of glnB was provided in trans, suggesting that the gene or gene product is essential for growth under the conditions tested.
authors.affiliation: Section of Microbiology, University of California, One Shields Avenue, Davis, CA 95616, USA.
authors.forename: Thomas E
authors.initials: TE
authors.lastname: Hanson
authors.affiliation: Lehrstuhl für Mikrobiologie der Universität München, Maria-Ward-Str. 1a, D-80638 München, Germany.
authors.forename: Karl
authors.initials: K
authors.lastname: Forchhammer
authors.affiliation: Unité de Physiologie Microbienne, Département de Biochimie et Génétique Moléculaire, Institut Pasteur, 28 rue du Docteur Roux, 75724 Paris Cedex 15, France.
authors.forename: Nicole Tandeau
authors.initials: NT
authors.lastname: de Marsac
authors.affiliation: Section of Microbiology, University of California, One Shields Avenue, Davis, CA 95616, USA.
authors.forename: John C
authors.initials: JC
authors.lastname: Meeks
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics / Q000302:isolation & purification / Q000502:physiology*; D015152:Blotting, Northern; D015139:Blotting, Southern; D000458:Cyanobacteria / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D005798:Genes, Bacterial / Q000235:genetics*; D015151:Immunoblotting; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D051922:PII Nitrogen Regulatory Proteins; D016415:Sequence Alignment
chemical_list: D001426:Bacterial Proteins; D051922:PII Nitrogen Regulatory Proteins; C404143:PIID regulatory protein, Bacteria