Characterization of the glnB gene product of Nostoc punctiforme strain ATCC 29133: glnB or the PII protein may be essential.
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.
Hanson
Thomas E
TE
Section of Microbiology, University of California, One Shields Avenue, Davis, CA 95616, USA.
Forchhammer
Karl
K
Lehrstuhl für Mikrobiologie der Universität München, Maria-Ward-Str. 1a, D-80638 München, Germany.
de Marsac
Nicole Tandeau
NT
Unité de Physiologie Microbienne, Département de Biochimie et Génétique Moléculaire, Institut Pasteur, 28 rue du Docteur Roux, 75724 Paris Cedex 15, France.
Meeks
John C
JC
Section of Microbiology, University of California, One Shields Avenue, Davis, CA 95616, USA.
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
D001426:Bacterial Proteins; D051922:PII Nitrogen Regulatory Proteins; C404143:PIID regulatory protein, Bacteria